[1] Energy use in solar cookers, solar distillation plants, solar power plants is known as –
A.
chemical energy
B.
solar energy
C.
thermal energy
D.
nuclear energy
Ans:
solar energy
Explanation :
Solar energy is radiant light and heat from the Sun that is harnessed using a range of ever-evolving technologies such as solar heating, solar thermal energy, solar architecture, molten salt power plants and artificial photosynthesis.
[2] 'Vinegar' is a commercial name of –
A.
Oxalic acid
B.
Hydrochloric acid
C.
Acetic acid
D.
Citric acid
Ans:
Acetic acid
Explanation :
Vinegar is a liquid substance consisting mainly of acetic acid (CH3CO2H) and water, the acetic acid being produced through the fermentation of ethanol by acetic acid bacteria. It is today mainly used in the kitchen as a general cooking ingredient.
[3] Which metal does not undergo corrosion due to the formation of oxide layer?
A.
Copper
B.
Iron
C.
Aluminium
D.
Zinc
Ans:
Aluminium
Explanation :
Corrosion is an oxidation reaction with atmospheric oxygen in the presence of water on the surface of a metal. Iron corrodes more quickly than most other transition metals to form an iron oxide. Aluminium also undergoes an oxidation reaction, but does not oxidize and corrode as quickly as its reactivity suggests. Once a thin oxide layer of Al2O3 has formed on the surface, it forms a barrier to oxygen and water to prevent further corrosion of the aluminium.
[4] The acid present in red ants is –
A.
Acetic acid
B.
Butyric acid
C.
Caproic acid
D.
Formic acid
Ans:
Formic acid
Explanation :
Formic acid is the simplest carboxylic acid. It is an important intermediate in chemical synthesis and occurs naturally, most notably in the venom of bee and ant stings. In fact, its name comes from the Latin word for ant. Formica, referring to its early isolation by the distillation of ant bodies.
[5] The metal extracted from Bauxite is –
A.
Silver
B.
Copper
C.
Manganese
D.
Aluminum
Ans:
Aluminum
Explanation :
Bauxite is an aluminium ore and is the main source of aluminium. Approximately 70% to 80% of the world's dry bauxite production is processed first into alumina, and then into aluminium by electrolysis as of 2010. Usually, bauxite ore is heated in a pressure vessel along with a sodium hydroxide solution at a temperature of 150 to 200 °C. At these temperatures, the aluminium is dissolved as an aluminate (the Bayer process).
[6] pH value between 6.5-7.5 makes the soil -
A.
Basic
B.
Neutral
C.
Acidic
D.
None of these
Ans:
None of these
Explanation :
In chemistry, pH is a measure of the activity of the (solvated) hydrogen ion. P [H], which measures the hydrogen ion concentration is closely related to, and is often written as, pH. Pure water has a pH very close to 7 at 25°C. Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline. A pH of 7 is treated as neutral.
[7] The metal chiefly used for galvanizing iron is:
A.
Zine
B.
Mercury
C.
Cadmium
D.
Tin
Ans:
Zine
Explanation :
Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. In current use, the term refers to the coating of steel or iron with zinc. This is done to prevent rusting of the ferrous item. The value of galvanizing stems from the corrosion resistance of zinc, which, under most service conditions, is considerably greater than that of iron and steel.
[8] Submarines move under water. They have engines that run on -
A.
Petrol and oxygen
B.
Diesel
C.
Batteries
D.
Steam
Ans:
Diesel
Explanation :
Early submarines used a direct mechanical connection between the engine and propeller, switching between diesel engines for surface running, and electric motors for submerged propulsion. Diesel- electric submarines have a stealth advantage over their nuclear Counterparts.
[9] The Bhopal gas tragedy was caused by the gas -
A.
Methyl chloride
B.
Methyl Iso Cyanide
C.
Methyl Iso Cyanate
D.
Methyl Cyanide
Ans:
Methyl Iso Cyanate
Explanation :
The Bhopal disaster occurred on the night of 2-3 December 1984 at the Union Carbide India Limited (UCIL) pesticide plant in Bhopal, Madhya Pradesh. Over 500,000 people were exposed to methyl isocyanate has and other chemicals. The toxic substance made its way in and around the shantytowns located near the plant.
[10] The wine is prepared by the process of -
A.
fermentation
B.
catalysation
C.
conjugation
D.
displacement
Ans:
fermentation
Explanation :
After the destemmer the wine is pumped into tanks to begin fermentation. The process of fermentation in winemaking turns grape juice into an alcoholic beverage.
[11] Fission and fusion are called -
A.
molecular reactions
B.
potential reactions
C.
nuclear reactions
D.
heat reactions
Ans:
nuclear reactions
Explanation :
The energy harnessed in nuclei is released in nuclear reactions. Fission is the splitting of a heavy nucleus into lighter nuclei and fusion is the combining of nuclei to form a bigger and heavier nucleus. Fission and fusion are called nuclear reactions
[12] Acids on reacting with metal carbonates release which of the following gases?
A.
Hydrogen sulphide
B.
Carbon Dioxide
C.
Propane
D.
Hydrogen
Ans:
Carbon Dioxide
Explanation :
When an acid reacts with a metal carbonate, a salt, water and carbon dioxide are produced: Acid + metal carbonate → salt + water + carbon dioxide
[13] Which of the following is released during photosynthesis?
A.
Oxygen
B.
Carbon dioxide
C.
Energy
D.
Light
Ans:
Oxygen
Explanation :
Plants use photosynthesis as a way of producing glucose. They take in light energy from the sun and water and carbon dioxide from the air. This is then used to produce oxygen and glucose. 6CO2 + 6 H2O → C6H12O6 + 6O2
[14] Who discovered electron?
A.
E. Goldstien
B.
J. J. Thomson
C.
Ernest Rutherford
D.
J. Chadwick
Ans:
J. J. Thomson
Explanation :
J.J. Thomson is credited with the discovery and identification of the electron. Thomson, in 1897, was the first to suggest that one of the fundamental units was more than 1,000 times smaller than an atom, suggesting the sub atomic particle now known as the electron.
[15] Which of the following is also known as Carbolic Acid?
A.
Phenol
B.
Hydroxide
C.
Sulphuric Acid
D.
Ethanol
Ans:
Phenol
Explanation :
Phenol is also known as carbolic acid. It is an aromatic organic compound with the molecular formula C6H5OH. Phenol and its chemical derivatives are essential for production of polycarbonates, epoxies, Bakelite, nylon, detergents, herbicides such as phenoxy herbicides, and numerous pharmaceutical drugs.
[16] Galvanization of iron is carried out using –
A.
Zinc
B.
Tin
C.
Copper
D.
Chromium
Ans:
Zinc
Explanation :
Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. The term is derived from the name of Italian scientist Luigi Galvani. Although galvanization can be done with electrochemical and electrode position processes, the most common method in current use is hot-dip galvanization, in which steel parts are submerged in a bath of molten zinc.
[17] Cokking gas is a mixture of -
A.
methane and ethylene
B.
carbon dioxide and oxygen
C.
butane and propane
D.
carbon monoxide and carbon dioxide
Ans:
butane and propane
Explanation :
Liquefied petroleum gas, also called LPG, GPL, LP Gas, liquid petroleum gas or simply propane or butane, is a flammable mixture of hydrocarbon gases used as a fuel in heating appliances and vehicles. It is increasingly used as an aerosol propellant and a refrigerant, replacing chlorofluorocarbons in an effort to reduce damage to the ozone layer. When specifically used as a vehicle fuel it is often referred to as auto gas.
[18] The purest form of water is –
A.
tap water
B.
rain water
C.
ground water
D.
distilled water
Ans:
rain water
Explanation :
Rain is liquid water in the form of droplets that have condensed from atmospheric water vapor and then precipitated—that is, become heavy enough to fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides suitable conditions for many types of ecosystem, as well as water for hydroelectric power plants and crop irrigation. The major cause of rain production is moisture moving along three-dimensional zones of temperature and moisture contrasts known as weather fronts.
[19] The main constituent of biogas is –
A.
oxygen
B.
methane
C.
acetic acid
D.
methyl alcohol
Ans:
methane
Explanation :
Biogas typically refers to a gas produced by breakdown of organic matter in the absence of oxygen. Organic waste such as dead plant and animal material, animal feces, and kitchen waste can be converted into a gaseous fuel called biogas. Biogas originates from biogenic material and is a type of bio fuel. Biogas is produced by the anaerobic digestion or fermentation of biodegradable materials such as biomass, manure, sewage, municipal waste, green waste, plant material, and crops.
[20] Which metal is extracted from sea water?
A.
Potassium
B.
Magnesium
C.
Aluminium
D.
Beryllium
Ans:
Magnesium
Explanation :
The metal is now mainly obtained by electrolysis of magnesium salts obtained from brine. Commercially, the chief use for the metal is as an alloying agent to make aluminium-magnesium alloys, sometimes called "magnalium" or "magnelium". Since magnesium is less dense than aluminium, these alloys are prized for their relative lightness and strength. Magnesium is the fourth most common element in the Earth as a whole (behind iron, oxygen and silicon), making up 13% of the planet's mass and a large fraction of the planet's mantle.
[21] Percentage of lead in lead pencils is –
A.
0
B.
31-66
C.
40
D.
80
Ans:
0
Explanation :
There is no lead in pencils. Rather, the core is made up of non-toxic mineral called graphite. The common name "pencil lead" is due to an historic association with the stylus made of lead in ancient Roman times. Most pencil cores are made of graphite mixed with a clay binder, leaving grey or black marks that can be easily erased. Graphite pencils are used for both writing and drawing, and the result is durable: although writing can usually be removed with an eraser, it is resistant to moisture, most chemicals, ultraviolet radiation and natural aging.
[22] When formaldehyde and potassium hydroxide are heated, we get –
A.
Acetylene
B.
Methyl alcohol
C.
Methane
D.
Ethyl formate
Ans:
Methyl alcohol
Explanation :
When formaldehyde and potassium hydroxide are heated,we get methyl alcohol and formic acid. it is cannizarroo reaction. The Cannizzaro reaction, named after its discoverer StanislaoCannizzaro, is a chemical reaction that involves the base-induced disproportionation of an aldehyde. Cannizzaro first accomplished this transformation in 1853, when he obtained benzyl alcohol and potassium benzoate from the treatment of benzaldehyde with potash (potassium carbonate). More typically, the reaction would be conducted with sodium or potassium hydroxide. The oxidation product is a salt of a carboxylic acid and the reduction product is an alcohol.
[23] When conc. H2SO4 is added to diy KNO3, brown fumes are evolved. These fumes are due to –
A.
SO3
B.
SO2
C.
NO2
D.
N2O
Ans:
NO2
Explanation :
When concentrated hydrosulphuric acid is added to dry potassium nitrate brown fumes are evolved and these fumes are evolved due to the formation of nitrogen dioxide. Nitrogen dioxide is the chemical compound with the formula NO2. It is one of several nitrogen oxides. NO2 is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year. This reddish-brown toxic gas has a characteristic sharp, biting odour and is a prominent air pollutant. Nitrogen dioxide is a paramagnetic and bent molecule.
[24] Pasteurisation of milk means –
A.
heating of milk to above 72°C
B.
heating of milk to above 62°C
C.
cooling of milk to about 62°C
D.
cooling of milk to about 10°C
Ans:
heating of milk to above 62°C
Explanation :
Pasteurization typically uses temperatures below boiling, since at very high temperatures, casein micelles will irreversibly aggregate, or “curdle”. The two main types of pasteurization used today are: hightemperature, short-time (HTST) and “extended shelf life” (ESL) treatment. Ultra-high temperature (UHT or ultra-heat-treated) is also used for milk treatment. In the HTST process, milk is forced between metal plates or through pipes heated on the outside by hot water, and is heated to 71.7degree C (161degree F) for 15– 20 seconds. UHT processing holds the milk at a temperature of 135degree C (275degree F) for a minimum of one second. ESL milk has a microbial filtration step and lower temperatures than UHT milk. Milk simply labeled “pasteurized” is usually treated with the HTST method, whereas milk labeled “ultrapasteurized” or simply “UHT” has been treated with the UHT method. A less conventional but US FDAlegal alternative (typically for home pasteurization) is to heat milk at 145 degree F (63 degree C) for 30 minutes.
[25] Aluminium can be purified by –
A.
oxidation
B.
distillation
C.
electrolysis
D.
ozonolysis
Ans:
electrolysis
Explanation :
Electrolysis is a method of using a direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially highly important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell. Aluminum is extracted from its oxide ore “Bauxite”. Electrolytic smelting of alumina was originally cost-prohibitive in part because of the high melting point of alumina, or aluminium oxide. Many minerals, however, will dissolve into a second already molten mineral, even if the temperature of the melt is significantly lower than the melting point of the first mineral. Molten cryolite was discovered to dissolve alumina at temperatures significantly lower than the melting point of pure alumina without interfering in the smelting process.
Explanation :
Solar energy is radiant light and heat from the Sun that is harnessed using a range of ever-evolving technologies such as solar heating, solar thermal energy, solar architecture, molten salt power plants and artificial photosynthesis.
[2] 'Vinegar' is a commercial name of –
A.
Oxalic acid
B.
Hydrochloric acid
C.
Acetic acid
D.
Citric acid
Ans:
Acetic acid
Explanation :
Vinegar is a liquid substance consisting mainly of acetic acid (CH3CO2H) and water, the acetic acid being produced through the fermentation of ethanol by acetic acid bacteria. It is today mainly used in the kitchen as a general cooking ingredient.
[3] Which metal does not undergo corrosion due to the formation of oxide layer?
A.
Copper
B.
Iron
C.
Aluminium
D.
Zinc
Ans:
Aluminium
Explanation :
Corrosion is an oxidation reaction with atmospheric oxygen in the presence of water on the surface of a metal. Iron corrodes more quickly than most other transition metals to form an iron oxide. Aluminium also undergoes an oxidation reaction, but does not oxidize and corrode as quickly as its reactivity suggests. Once a thin oxide layer of Al2O3 has formed on the surface, it forms a barrier to oxygen and water to prevent further corrosion of the aluminium.
[4] The acid present in red ants is –
A.
Acetic acid
B.
Butyric acid
C.
Caproic acid
D.
Formic acid
Ans:
Formic acid
Explanation :
Formic acid is the simplest carboxylic acid. It is an important intermediate in chemical synthesis and occurs naturally, most notably in the venom of bee and ant stings. In fact, its name comes from the Latin word for ant. Formica, referring to its early isolation by the distillation of ant bodies.
[5] The metal extracted from Bauxite is –
A.
Silver
B.
Copper
C.
Manganese
D.
Aluminum
Ans:
Aluminum
Explanation :
Bauxite is an aluminium ore and is the main source of aluminium. Approximately 70% to 80% of the world's dry bauxite production is processed first into alumina, and then into aluminium by electrolysis as of 2010. Usually, bauxite ore is heated in a pressure vessel along with a sodium hydroxide solution at a temperature of 150 to 200 °C. At these temperatures, the aluminium is dissolved as an aluminate (the Bayer process).
[6] pH value between 6.5-7.5 makes the soil -
A.
Basic
B.
Neutral
C.
Acidic
D.
None of these
Ans:
None of these
Explanation :
In chemistry, pH is a measure of the activity of the (solvated) hydrogen ion. P [H], which measures the hydrogen ion concentration is closely related to, and is often written as, pH. Pure water has a pH very close to 7 at 25°C. Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline. A pH of 7 is treated as neutral.
[7] The metal chiefly used for galvanizing iron is:
A.
Zine
B.
Mercury
C.
Cadmium
D.
Tin
Ans:
Zine
Explanation :
Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. In current use, the term refers to the coating of steel or iron with zinc. This is done to prevent rusting of the ferrous item. The value of galvanizing stems from the corrosion resistance of zinc, which, under most service conditions, is considerably greater than that of iron and steel.
[8] Submarines move under water. They have engines that run on -
A.
Petrol and oxygen
B.
Diesel
C.
Batteries
D.
Steam
Ans:
Diesel
Explanation :
Early submarines used a direct mechanical connection between the engine and propeller, switching between diesel engines for surface running, and electric motors for submerged propulsion. Diesel- electric submarines have a stealth advantage over their nuclear Counterparts.
[9] The Bhopal gas tragedy was caused by the gas -
A.
Methyl chloride
B.
Methyl Iso Cyanide
C.
Methyl Iso Cyanate
D.
Methyl Cyanide
Ans:
Methyl Iso Cyanate
Explanation :
The Bhopal disaster occurred on the night of 2-3 December 1984 at the Union Carbide India Limited (UCIL) pesticide plant in Bhopal, Madhya Pradesh. Over 500,000 people were exposed to methyl isocyanate has and other chemicals. The toxic substance made its way in and around the shantytowns located near the plant.
[10] The wine is prepared by the process of -
A.
fermentation
B.
catalysation
C.
conjugation
D.
displacement
Ans:
fermentation
Explanation :
After the destemmer the wine is pumped into tanks to begin fermentation. The process of fermentation in winemaking turns grape juice into an alcoholic beverage.
[11] Fission and fusion are called -
A.
molecular reactions
B.
potential reactions
C.
nuclear reactions
D.
heat reactions
Ans:
nuclear reactions
Explanation :
The energy harnessed in nuclei is released in nuclear reactions. Fission is the splitting of a heavy nucleus into lighter nuclei and fusion is the combining of nuclei to form a bigger and heavier nucleus. Fission and fusion are called nuclear reactions
[12] Acids on reacting with metal carbonates release which of the following gases?
A.
Hydrogen sulphide
B.
Carbon Dioxide
C.
Propane
D.
Hydrogen
Ans:
Carbon Dioxide
Explanation :
When an acid reacts with a metal carbonate, a salt, water and carbon dioxide are produced: Acid + metal carbonate → salt + water + carbon dioxide
[13] Which of the following is released during photosynthesis?
A.
Oxygen
B.
Carbon dioxide
C.
Energy
D.
Light
Ans:
Oxygen
Explanation :
Plants use photosynthesis as a way of producing glucose. They take in light energy from the sun and water and carbon dioxide from the air. This is then used to produce oxygen and glucose. 6CO2 + 6 H2O → C6H12O6 + 6O2
[14] Who discovered electron?
A.
E. Goldstien
B.
J. J. Thomson
C.
Ernest Rutherford
D.
J. Chadwick
Ans:
J. J. Thomson
Explanation :
J.J. Thomson is credited with the discovery and identification of the electron. Thomson, in 1897, was the first to suggest that one of the fundamental units was more than 1,000 times smaller than an atom, suggesting the sub atomic particle now known as the electron.
[15] Which of the following is also known as Carbolic Acid?
A.
Phenol
B.
Hydroxide
C.
Sulphuric Acid
D.
Ethanol
Ans:
Phenol
Explanation :
Phenol is also known as carbolic acid. It is an aromatic organic compound with the molecular formula C6H5OH. Phenol and its chemical derivatives are essential for production of polycarbonates, epoxies, Bakelite, nylon, detergents, herbicides such as phenoxy herbicides, and numerous pharmaceutical drugs.
[16] Galvanization of iron is carried out using –
A.
Zinc
B.
Tin
C.
Copper
D.
Chromium
Ans:
Zinc
Explanation :
Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. The term is derived from the name of Italian scientist Luigi Galvani. Although galvanization can be done with electrochemical and electrode position processes, the most common method in current use is hot-dip galvanization, in which steel parts are submerged in a bath of molten zinc.
[17] Cokking gas is a mixture of -
A.
methane and ethylene
B.
carbon dioxide and oxygen
C.
butane and propane
D.
carbon monoxide and carbon dioxide
Ans:
butane and propane
Explanation :
Liquefied petroleum gas, also called LPG, GPL, LP Gas, liquid petroleum gas or simply propane or butane, is a flammable mixture of hydrocarbon gases used as a fuel in heating appliances and vehicles. It is increasingly used as an aerosol propellant and a refrigerant, replacing chlorofluorocarbons in an effort to reduce damage to the ozone layer. When specifically used as a vehicle fuel it is often referred to as auto gas.
[18] The purest form of water is –
A.
tap water
B.
rain water
C.
ground water
D.
distilled water
Ans:
rain water
Explanation :
Rain is liquid water in the form of droplets that have condensed from atmospheric water vapor and then precipitated—that is, become heavy enough to fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides suitable conditions for many types of ecosystem, as well as water for hydroelectric power plants and crop irrigation. The major cause of rain production is moisture moving along three-dimensional zones of temperature and moisture contrasts known as weather fronts.
[19] The main constituent of biogas is –
A.
oxygen
B.
methane
C.
acetic acid
D.
methyl alcohol
Ans:
methane
Explanation :
Biogas typically refers to a gas produced by breakdown of organic matter in the absence of oxygen. Organic waste such as dead plant and animal material, animal feces, and kitchen waste can be converted into a gaseous fuel called biogas. Biogas originates from biogenic material and is a type of bio fuel. Biogas is produced by the anaerobic digestion or fermentation of biodegradable materials such as biomass, manure, sewage, municipal waste, green waste, plant material, and crops.
[20] Which metal is extracted from sea water?
A.
Potassium
B.
Magnesium
C.
Aluminium
D.
Beryllium
Ans:
Magnesium
Explanation :
The metal is now mainly obtained by electrolysis of magnesium salts obtained from brine. Commercially, the chief use for the metal is as an alloying agent to make aluminium-magnesium alloys, sometimes called "magnalium" or "magnelium". Since magnesium is less dense than aluminium, these alloys are prized for their relative lightness and strength. Magnesium is the fourth most common element in the Earth as a whole (behind iron, oxygen and silicon), making up 13% of the planet's mass and a large fraction of the planet's mantle.
[21] Percentage of lead in lead pencils is –
A.
0
B.
31-66
C.
40
D.
80
Ans:
0
Explanation :
There is no lead in pencils. Rather, the core is made up of non-toxic mineral called graphite. The common name "pencil lead" is due to an historic association with the stylus made of lead in ancient Roman times. Most pencil cores are made of graphite mixed with a clay binder, leaving grey or black marks that can be easily erased. Graphite pencils are used for both writing and drawing, and the result is durable: although writing can usually be removed with an eraser, it is resistant to moisture, most chemicals, ultraviolet radiation and natural aging.
[22] When formaldehyde and potassium hydroxide are heated, we get –
A.
Acetylene
B.
Methyl alcohol
C.
Methane
D.
Ethyl formate
Ans:
Methyl alcohol
Explanation :
When formaldehyde and potassium hydroxide are heated,we get methyl alcohol and formic acid. it is cannizarroo reaction. The Cannizzaro reaction, named after its discoverer StanislaoCannizzaro, is a chemical reaction that involves the base-induced disproportionation of an aldehyde. Cannizzaro first accomplished this transformation in 1853, when he obtained benzyl alcohol and potassium benzoate from the treatment of benzaldehyde with potash (potassium carbonate). More typically, the reaction would be conducted with sodium or potassium hydroxide. The oxidation product is a salt of a carboxylic acid and the reduction product is an alcohol.
[23] When conc. H2SO4 is added to diy KNO3, brown fumes are evolved. These fumes are due to –
A.
SO3
B.
SO2
C.
NO2
D.
N2O
Ans:
NO2
Explanation :
When concentrated hydrosulphuric acid is added to dry potassium nitrate brown fumes are evolved and these fumes are evolved due to the formation of nitrogen dioxide. Nitrogen dioxide is the chemical compound with the formula NO2. It is one of several nitrogen oxides. NO2 is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year. This reddish-brown toxic gas has a characteristic sharp, biting odour and is a prominent air pollutant. Nitrogen dioxide is a paramagnetic and bent molecule.
[24] Pasteurisation of milk means –
A.
heating of milk to above 72°C
B.
heating of milk to above 62°C
C.
cooling of milk to about 62°C
D.
cooling of milk to about 10°C
Ans:
heating of milk to above 62°C
Explanation :
Pasteurization typically uses temperatures below boiling, since at very high temperatures, casein micelles will irreversibly aggregate, or “curdle”. The two main types of pasteurization used today are: hightemperature, short-time (HTST) and “extended shelf life” (ESL) treatment. Ultra-high temperature (UHT or ultra-heat-treated) is also used for milk treatment. In the HTST process, milk is forced between metal plates or through pipes heated on the outside by hot water, and is heated to 71.7degree C (161degree F) for 15– 20 seconds. UHT processing holds the milk at a temperature of 135degree C (275degree F) for a minimum of one second. ESL milk has a microbial filtration step and lower temperatures than UHT milk. Milk simply labeled “pasteurized” is usually treated with the HTST method, whereas milk labeled “ultrapasteurized” or simply “UHT” has been treated with the UHT method. A less conventional but US FDAlegal alternative (typically for home pasteurization) is to heat milk at 145 degree F (63 degree C) for 30 minutes.
[25] Aluminium can be purified by –
A.
oxidation
B.
distillation
C.
electrolysis
D.
ozonolysis
Ans:
electrolysis
Explanation :
Electrolysis is a method of using a direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially highly important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell. Aluminum is extracted from its oxide ore “Bauxite”. Electrolytic smelting of alumina was originally cost-prohibitive in part because of the high melting point of alumina, or aluminium oxide. Many minerals, however, will dissolve into a second already molten mineral, even if the temperature of the melt is significantly lower than the melting point of the first mineral. Molten cryolite was discovered to dissolve alumina at temperatures significantly lower than the melting point of pure alumina without interfering in the smelting process.
Explanation :
Corrosion is an oxidation reaction with atmospheric oxygen in the presence of water on the surface of a metal. Iron corrodes more quickly than most other transition metals to form an iron oxide. Aluminium also undergoes an oxidation reaction, but does not oxidize and corrode as quickly as its reactivity suggests. Once a thin oxide layer of Al2O3 has formed on the surface, it forms a barrier to oxygen and water to prevent further corrosion of the aluminium.
[4] The acid present in red ants is –
A.
Acetic acid
B.
Butyric acid
C.
Caproic acid
D.
Formic acid
Ans:
Formic acid
Explanation :
Formic acid is the simplest carboxylic acid. It is an important intermediate in chemical synthesis and occurs naturally, most notably in the venom of bee and ant stings. In fact, its name comes from the Latin word for ant. Formica, referring to its early isolation by the distillation of ant bodies.
[5] The metal extracted from Bauxite is –
A.
Silver
B.
Copper
C.
Manganese
D.
Aluminum
Ans:
Aluminum
Explanation :
Bauxite is an aluminium ore and is the main source of aluminium. Approximately 70% to 80% of the world's dry bauxite production is processed first into alumina, and then into aluminium by electrolysis as of 2010. Usually, bauxite ore is heated in a pressure vessel along with a sodium hydroxide solution at a temperature of 150 to 200 °C. At these temperatures, the aluminium is dissolved as an aluminate (the Bayer process).
[6] pH value between 6.5-7.5 makes the soil -
A.
Basic
B.
Neutral
C.
Acidic
D.
None of these
Ans:
None of these
Explanation :
In chemistry, pH is a measure of the activity of the (solvated) hydrogen ion. P [H], which measures the hydrogen ion concentration is closely related to, and is often written as, pH. Pure water has a pH very close to 7 at 25°C. Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline. A pH of 7 is treated as neutral.
[7] The metal chiefly used for galvanizing iron is:
A.
Zine
B.
Mercury
C.
Cadmium
D.
Tin
Ans:
Zine
Explanation :
Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. In current use, the term refers to the coating of steel or iron with zinc. This is done to prevent rusting of the ferrous item. The value of galvanizing stems from the corrosion resistance of zinc, which, under most service conditions, is considerably greater than that of iron and steel.
[8] Submarines move under water. They have engines that run on -
A.
Petrol and oxygen
B.
Diesel
C.
Batteries
D.
Steam
Ans:
Diesel
Explanation :
Early submarines used a direct mechanical connection between the engine and propeller, switching between diesel engines for surface running, and electric motors for submerged propulsion. Diesel- electric submarines have a stealth advantage over their nuclear Counterparts.
[9] The Bhopal gas tragedy was caused by the gas -
A.
Methyl chloride
B.
Methyl Iso Cyanide
C.
Methyl Iso Cyanate
D.
Methyl Cyanide
Ans:
Methyl Iso Cyanate
Explanation :
The Bhopal disaster occurred on the night of 2-3 December 1984 at the Union Carbide India Limited (UCIL) pesticide plant in Bhopal, Madhya Pradesh. Over 500,000 people were exposed to methyl isocyanate has and other chemicals. The toxic substance made its way in and around the shantytowns located near the plant.
[10] The wine is prepared by the process of -
A.
fermentation
B.
catalysation
C.
conjugation
D.
displacement
Ans:
fermentation
Explanation :
After the destemmer the wine is pumped into tanks to begin fermentation. The process of fermentation in winemaking turns grape juice into an alcoholic beverage.
[11] Fission and fusion are called -
A.
molecular reactions
B.
potential reactions
C.
nuclear reactions
D.
heat reactions
Ans:
nuclear reactions
Explanation :
The energy harnessed in nuclei is released in nuclear reactions. Fission is the splitting of a heavy nucleus into lighter nuclei and fusion is the combining of nuclei to form a bigger and heavier nucleus. Fission and fusion are called nuclear reactions
[12] Acids on reacting with metal carbonates release which of the following gases?
A.
Hydrogen sulphide
B.
Carbon Dioxide
C.
Propane
D.
Hydrogen
Ans:
Carbon Dioxide
Explanation :
When an acid reacts with a metal carbonate, a salt, water and carbon dioxide are produced: Acid + metal carbonate → salt + water + carbon dioxide
[13] Which of the following is released during photosynthesis?
A.
Oxygen
B.
Carbon dioxide
C.
Energy
D.
Light
Ans:
Oxygen
Explanation :
Plants use photosynthesis as a way of producing glucose. They take in light energy from the sun and water and carbon dioxide from the air. This is then used to produce oxygen and glucose. 6CO2 + 6 H2O → C6H12O6 + 6O2
[14] Who discovered electron?
A.
E. Goldstien
B.
J. J. Thomson
C.
Ernest Rutherford
D.
J. Chadwick
Ans:
J. J. Thomson
Explanation :
J.J. Thomson is credited with the discovery and identification of the electron. Thomson, in 1897, was the first to suggest that one of the fundamental units was more than 1,000 times smaller than an atom, suggesting the sub atomic particle now known as the electron.
[15] Which of the following is also known as Carbolic Acid?
A.
Phenol
B.
Hydroxide
C.
Sulphuric Acid
D.
Ethanol
Ans:
Phenol
Explanation :
Phenol is also known as carbolic acid. It is an aromatic organic compound with the molecular formula C6H5OH. Phenol and its chemical derivatives are essential for production of polycarbonates, epoxies, Bakelite, nylon, detergents, herbicides such as phenoxy herbicides, and numerous pharmaceutical drugs.
[16] Galvanization of iron is carried out using –
A.
Zinc
B.
Tin
C.
Copper
D.
Chromium
Ans:
Zinc
Explanation :
Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. The term is derived from the name of Italian scientist Luigi Galvani. Although galvanization can be done with electrochemical and electrode position processes, the most common method in current use is hot-dip galvanization, in which steel parts are submerged in a bath of molten zinc.
[17] Cokking gas is a mixture of -
A.
methane and ethylene
B.
carbon dioxide and oxygen
C.
butane and propane
D.
carbon monoxide and carbon dioxide
Ans:
butane and propane
Explanation :
Liquefied petroleum gas, also called LPG, GPL, LP Gas, liquid petroleum gas or simply propane or butane, is a flammable mixture of hydrocarbon gases used as a fuel in heating appliances and vehicles. It is increasingly used as an aerosol propellant and a refrigerant, replacing chlorofluorocarbons in an effort to reduce damage to the ozone layer. When specifically used as a vehicle fuel it is often referred to as auto gas.
[18] The purest form of water is –
A.
tap water
B.
rain water
C.
ground water
D.
distilled water
Ans:
rain water
Explanation :
Rain is liquid water in the form of droplets that have condensed from atmospheric water vapor and then precipitated—that is, become heavy enough to fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides suitable conditions for many types of ecosystem, as well as water for hydroelectric power plants and crop irrigation. The major cause of rain production is moisture moving along three-dimensional zones of temperature and moisture contrasts known as weather fronts.
[19] The main constituent of biogas is –
A.
oxygen
B.
methane
C.
acetic acid
D.
methyl alcohol
Ans:
methane
Explanation :
Biogas typically refers to a gas produced by breakdown of organic matter in the absence of oxygen. Organic waste such as dead plant and animal material, animal feces, and kitchen waste can be converted into a gaseous fuel called biogas. Biogas originates from biogenic material and is a type of bio fuel. Biogas is produced by the anaerobic digestion or fermentation of biodegradable materials such as biomass, manure, sewage, municipal waste, green waste, plant material, and crops.
[20] Which metal is extracted from sea water?
A.
Potassium
B.
Magnesium
C.
Aluminium
D.
Beryllium
Ans:
Magnesium
Explanation :
The metal is now mainly obtained by electrolysis of magnesium salts obtained from brine. Commercially, the chief use for the metal is as an alloying agent to make aluminium-magnesium alloys, sometimes called "magnalium" or "magnelium". Since magnesium is less dense than aluminium, these alloys are prized for their relative lightness and strength. Magnesium is the fourth most common element in the Earth as a whole (behind iron, oxygen and silicon), making up 13% of the planet's mass and a large fraction of the planet's mantle.
[21] Percentage of lead in lead pencils is –
A.
0
B.
31-66
C.
40
D.
80
Ans:
0
Explanation :
There is no lead in pencils. Rather, the core is made up of non-toxic mineral called graphite. The common name "pencil lead" is due to an historic association with the stylus made of lead in ancient Roman times. Most pencil cores are made of graphite mixed with a clay binder, leaving grey or black marks that can be easily erased. Graphite pencils are used for both writing and drawing, and the result is durable: although writing can usually be removed with an eraser, it is resistant to moisture, most chemicals, ultraviolet radiation and natural aging.
[22] When formaldehyde and potassium hydroxide are heated, we get –
A.
Acetylene
B.
Methyl alcohol
C.
Methane
D.
Ethyl formate
Ans:
Methyl alcohol
Explanation :
When formaldehyde and potassium hydroxide are heated,we get methyl alcohol and formic acid. it is cannizarroo reaction. The Cannizzaro reaction, named after its discoverer StanislaoCannizzaro, is a chemical reaction that involves the base-induced disproportionation of an aldehyde. Cannizzaro first accomplished this transformation in 1853, when he obtained benzyl alcohol and potassium benzoate from the treatment of benzaldehyde with potash (potassium carbonate). More typically, the reaction would be conducted with sodium or potassium hydroxide. The oxidation product is a salt of a carboxylic acid and the reduction product is an alcohol.
[23] When conc. H2SO4 is added to diy KNO3, brown fumes are evolved. These fumes are due to –
A.
SO3
B.
SO2
C.
NO2
D.
N2O
Ans:
NO2
Explanation :
When concentrated hydrosulphuric acid is added to dry potassium nitrate brown fumes are evolved and these fumes are evolved due to the formation of nitrogen dioxide. Nitrogen dioxide is the chemical compound with the formula NO2. It is one of several nitrogen oxides. NO2 is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year. This reddish-brown toxic gas has a characteristic sharp, biting odour and is a prominent air pollutant. Nitrogen dioxide is a paramagnetic and bent molecule.
[24] Pasteurisation of milk means –
A.
heating of milk to above 72°C
B.
heating of milk to above 62°C
C.
cooling of milk to about 62°C
D.
cooling of milk to about 10°C
Ans:
heating of milk to above 62°C
Explanation :
Pasteurization typically uses temperatures below boiling, since at very high temperatures, casein micelles will irreversibly aggregate, or “curdle”. The two main types of pasteurization used today are: hightemperature, short-time (HTST) and “extended shelf life” (ESL) treatment. Ultra-high temperature (UHT or ultra-heat-treated) is also used for milk treatment. In the HTST process, milk is forced between metal plates or through pipes heated on the outside by hot water, and is heated to 71.7degree C (161degree F) for 15– 20 seconds. UHT processing holds the milk at a temperature of 135degree C (275degree F) for a minimum of one second. ESL milk has a microbial filtration step and lower temperatures than UHT milk. Milk simply labeled “pasteurized” is usually treated with the HTST method, whereas milk labeled “ultrapasteurized” or simply “UHT” has been treated with the UHT method. A less conventional but US FDAlegal alternative (typically for home pasteurization) is to heat milk at 145 degree F (63 degree C) for 30 minutes.
[25] Aluminium can be purified by –
A.
oxidation
B.
distillation
C.
electrolysis
D.
ozonolysis
Ans:
electrolysis
Explanation :
Electrolysis is a method of using a direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially highly important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell. Aluminum is extracted from its oxide ore “Bauxite”. Electrolytic smelting of alumina was originally cost-prohibitive in part because of the high melting point of alumina, or aluminium oxide. Many minerals, however, will dissolve into a second already molten mineral, even if the temperature of the melt is significantly lower than the melting point of the first mineral. Molten cryolite was discovered to dissolve alumina at temperatures significantly lower than the melting point of pure alumina without interfering in the smelting process.
Explanation :
Bauxite is an aluminium ore and is the main source of aluminium. Approximately 70% to 80% of the world's dry bauxite production is processed first into alumina, and then into aluminium by electrolysis as of 2010. Usually, bauxite ore is heated in a pressure vessel along with a sodium hydroxide solution at a temperature of 150 to 200 °C. At these temperatures, the aluminium is dissolved as an aluminate (the Bayer process).
[6] pH value between 6.5-7.5 makes the soil -
A.
Basic
B.
Neutral
C.
Acidic
D.
None of these
Ans:
None of these
Explanation :
In chemistry, pH is a measure of the activity of the (solvated) hydrogen ion. P [H], which measures the hydrogen ion concentration is closely related to, and is often written as, pH. Pure water has a pH very close to 7 at 25°C. Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline. A pH of 7 is treated as neutral.
[7] The metal chiefly used for galvanizing iron is:
A.
Zine
B.
Mercury
C.
Cadmium
D.
Tin
Ans:
Zine
Explanation :
Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. In current use, the term refers to the coating of steel or iron with zinc. This is done to prevent rusting of the ferrous item. The value of galvanizing stems from the corrosion resistance of zinc, which, under most service conditions, is considerably greater than that of iron and steel.
[8] Submarines move under water. They have engines that run on -
A.
Petrol and oxygen
B.
Diesel
C.
Batteries
D.
Steam
Ans:
Diesel
Explanation :
Early submarines used a direct mechanical connection between the engine and propeller, switching between diesel engines for surface running, and electric motors for submerged propulsion. Diesel- electric submarines have a stealth advantage over their nuclear Counterparts.
[9] The Bhopal gas tragedy was caused by the gas -
A.
Methyl chloride
B.
Methyl Iso Cyanide
C.
Methyl Iso Cyanate
D.
Methyl Cyanide
Ans:
Methyl Iso Cyanate
Explanation :
The Bhopal disaster occurred on the night of 2-3 December 1984 at the Union Carbide India Limited (UCIL) pesticide plant in Bhopal, Madhya Pradesh. Over 500,000 people were exposed to methyl isocyanate has and other chemicals. The toxic substance made its way in and around the shantytowns located near the plant.
[10] The wine is prepared by the process of -
A.
fermentation
B.
catalysation
C.
conjugation
D.
displacement
Ans:
fermentation
Explanation :
After the destemmer the wine is pumped into tanks to begin fermentation. The process of fermentation in winemaking turns grape juice into an alcoholic beverage.
[11] Fission and fusion are called -
A.
molecular reactions
B.
potential reactions
C.
nuclear reactions
D.
heat reactions
Ans:
nuclear reactions
Explanation :
The energy harnessed in nuclei is released in nuclear reactions. Fission is the splitting of a heavy nucleus into lighter nuclei and fusion is the combining of nuclei to form a bigger and heavier nucleus. Fission and fusion are called nuclear reactions
[12] Acids on reacting with metal carbonates release which of the following gases?
A.
Hydrogen sulphide
B.
Carbon Dioxide
C.
Propane
D.
Hydrogen
Ans:
Carbon Dioxide
Explanation :
When an acid reacts with a metal carbonate, a salt, water and carbon dioxide are produced: Acid + metal carbonate → salt + water + carbon dioxide
[13] Which of the following is released during photosynthesis?
A.
Oxygen
B.
Carbon dioxide
C.
Energy
D.
Light
Ans:
Oxygen
Explanation :
Plants use photosynthesis as a way of producing glucose. They take in light energy from the sun and water and carbon dioxide from the air. This is then used to produce oxygen and glucose. 6CO2 + 6 H2O → C6H12O6 + 6O2
[14] Who discovered electron?
A.
E. Goldstien
B.
J. J. Thomson
C.
Ernest Rutherford
D.
J. Chadwick
Ans:
J. J. Thomson
Explanation :
J.J. Thomson is credited with the discovery and identification of the electron. Thomson, in 1897, was the first to suggest that one of the fundamental units was more than 1,000 times smaller than an atom, suggesting the sub atomic particle now known as the electron.
[15] Which of the following is also known as Carbolic Acid?
A.
Phenol
B.
Hydroxide
C.
Sulphuric Acid
D.
Ethanol
Ans:
Phenol
Explanation :
Phenol is also known as carbolic acid. It is an aromatic organic compound with the molecular formula C6H5OH. Phenol and its chemical derivatives are essential for production of polycarbonates, epoxies, Bakelite, nylon, detergents, herbicides such as phenoxy herbicides, and numerous pharmaceutical drugs.
[16] Galvanization of iron is carried out using –
A.
Zinc
B.
Tin
C.
Copper
D.
Chromium
Ans:
Zinc
Explanation :
Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. The term is derived from the name of Italian scientist Luigi Galvani. Although galvanization can be done with electrochemical and electrode position processes, the most common method in current use is hot-dip galvanization, in which steel parts are submerged in a bath of molten zinc.
[17] Cokking gas is a mixture of -
A.
methane and ethylene
B.
carbon dioxide and oxygen
C.
butane and propane
D.
carbon monoxide and carbon dioxide
Ans:
butane and propane
Explanation :
Liquefied petroleum gas, also called LPG, GPL, LP Gas, liquid petroleum gas or simply propane or butane, is a flammable mixture of hydrocarbon gases used as a fuel in heating appliances and vehicles. It is increasingly used as an aerosol propellant and a refrigerant, replacing chlorofluorocarbons in an effort to reduce damage to the ozone layer. When specifically used as a vehicle fuel it is often referred to as auto gas.
[18] The purest form of water is –
A.
tap water
B.
rain water
C.
ground water
D.
distilled water
Ans:
rain water
Explanation :
Rain is liquid water in the form of droplets that have condensed from atmospheric water vapor and then precipitated—that is, become heavy enough to fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides suitable conditions for many types of ecosystem, as well as water for hydroelectric power plants and crop irrigation. The major cause of rain production is moisture moving along three-dimensional zones of temperature and moisture contrasts known as weather fronts.
[19] The main constituent of biogas is –
A.
oxygen
B.
methane
C.
acetic acid
D.
methyl alcohol
Ans:
methane
Explanation :
Biogas typically refers to a gas produced by breakdown of organic matter in the absence of oxygen. Organic waste such as dead plant and animal material, animal feces, and kitchen waste can be converted into a gaseous fuel called biogas. Biogas originates from biogenic material and is a type of bio fuel. Biogas is produced by the anaerobic digestion or fermentation of biodegradable materials such as biomass, manure, sewage, municipal waste, green waste, plant material, and crops.
[20] Which metal is extracted from sea water?
A.
Potassium
B.
Magnesium
C.
Aluminium
D.
Beryllium
Ans:
Magnesium
Explanation :
The metal is now mainly obtained by electrolysis of magnesium salts obtained from brine. Commercially, the chief use for the metal is as an alloying agent to make aluminium-magnesium alloys, sometimes called "magnalium" or "magnelium". Since magnesium is less dense than aluminium, these alloys are prized for their relative lightness and strength. Magnesium is the fourth most common element in the Earth as a whole (behind iron, oxygen and silicon), making up 13% of the planet's mass and a large fraction of the planet's mantle.
[21] Percentage of lead in lead pencils is –
A.
0
B.
31-66
C.
40
D.
80
Ans:
0
Explanation :
There is no lead in pencils. Rather, the core is made up of non-toxic mineral called graphite. The common name "pencil lead" is due to an historic association with the stylus made of lead in ancient Roman times. Most pencil cores are made of graphite mixed with a clay binder, leaving grey or black marks that can be easily erased. Graphite pencils are used for both writing and drawing, and the result is durable: although writing can usually be removed with an eraser, it is resistant to moisture, most chemicals, ultraviolet radiation and natural aging.
[22] When formaldehyde and potassium hydroxide are heated, we get –
A.
Acetylene
B.
Methyl alcohol
C.
Methane
D.
Ethyl formate
Ans:
Methyl alcohol
Explanation :
When formaldehyde and potassium hydroxide are heated,we get methyl alcohol and formic acid. it is cannizarroo reaction. The Cannizzaro reaction, named after its discoverer StanislaoCannizzaro, is a chemical reaction that involves the base-induced disproportionation of an aldehyde. Cannizzaro first accomplished this transformation in 1853, when he obtained benzyl alcohol and potassium benzoate from the treatment of benzaldehyde with potash (potassium carbonate). More typically, the reaction would be conducted with sodium or potassium hydroxide. The oxidation product is a salt of a carboxylic acid and the reduction product is an alcohol.
[23] When conc. H2SO4 is added to diy KNO3, brown fumes are evolved. These fumes are due to –
A.
SO3
B.
SO2
C.
NO2
D.
N2O
Ans:
NO2
Explanation :
When concentrated hydrosulphuric acid is added to dry potassium nitrate brown fumes are evolved and these fumes are evolved due to the formation of nitrogen dioxide. Nitrogen dioxide is the chemical compound with the formula NO2. It is one of several nitrogen oxides. NO2 is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year. This reddish-brown toxic gas has a characteristic sharp, biting odour and is a prominent air pollutant. Nitrogen dioxide is a paramagnetic and bent molecule.
[24] Pasteurisation of milk means –
A.
heating of milk to above 72°C
B.
heating of milk to above 62°C
C.
cooling of milk to about 62°C
D.
cooling of milk to about 10°C
Ans:
heating of milk to above 62°C
Explanation :
Pasteurization typically uses temperatures below boiling, since at very high temperatures, casein micelles will irreversibly aggregate, or “curdle”. The two main types of pasteurization used today are: hightemperature, short-time (HTST) and “extended shelf life” (ESL) treatment. Ultra-high temperature (UHT or ultra-heat-treated) is also used for milk treatment. In the HTST process, milk is forced between metal plates or through pipes heated on the outside by hot water, and is heated to 71.7degree C (161degree F) for 15– 20 seconds. UHT processing holds the milk at a temperature of 135degree C (275degree F) for a minimum of one second. ESL milk has a microbial filtration step and lower temperatures than UHT milk. Milk simply labeled “pasteurized” is usually treated with the HTST method, whereas milk labeled “ultrapasteurized” or simply “UHT” has been treated with the UHT method. A less conventional but US FDAlegal alternative (typically for home pasteurization) is to heat milk at 145 degree F (63 degree C) for 30 minutes.
[25] Aluminium can be purified by –
A.
oxidation
B.
distillation
C.
electrolysis
D.
ozonolysis
Ans:
electrolysis
Explanation :
Electrolysis is a method of using a direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially highly important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell. Aluminum is extracted from its oxide ore “Bauxite”. Electrolytic smelting of alumina was originally cost-prohibitive in part because of the high melting point of alumina, or aluminium oxide. Many minerals, however, will dissolve into a second already molten mineral, even if the temperature of the melt is significantly lower than the melting point of the first mineral. Molten cryolite was discovered to dissolve alumina at temperatures significantly lower than the melting point of pure alumina without interfering in the smelting process.
Explanation :
Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. In current use, the term refers to the coating of steel or iron with zinc. This is done to prevent rusting of the ferrous item. The value of galvanizing stems from the corrosion resistance of zinc, which, under most service conditions, is considerably greater than that of iron and steel.
[8] Submarines move under water. They have engines that run on -
A.
Petrol and oxygen
B.
Diesel
C.
Batteries
D.
Steam
Ans:
Diesel
Explanation :
Early submarines used a direct mechanical connection between the engine and propeller, switching between diesel engines for surface running, and electric motors for submerged propulsion. Diesel- electric submarines have a stealth advantage over their nuclear Counterparts.
[9] The Bhopal gas tragedy was caused by the gas -
A.
Methyl chloride
B.
Methyl Iso Cyanide
C.
Methyl Iso Cyanate
D.
Methyl Cyanide
Ans:
Methyl Iso Cyanate
Explanation :
The Bhopal disaster occurred on the night of 2-3 December 1984 at the Union Carbide India Limited (UCIL) pesticide plant in Bhopal, Madhya Pradesh. Over 500,000 people were exposed to methyl isocyanate has and other chemicals. The toxic substance made its way in and around the shantytowns located near the plant.
[10] The wine is prepared by the process of -
A.
fermentation
B.
catalysation
C.
conjugation
D.
displacement
Ans:
fermentation
Explanation :
After the destemmer the wine is pumped into tanks to begin fermentation. The process of fermentation in winemaking turns grape juice into an alcoholic beverage.
[11] Fission and fusion are called -
A.
molecular reactions
B.
potential reactions
C.
nuclear reactions
D.
heat reactions
Ans:
nuclear reactions
Explanation :
The energy harnessed in nuclei is released in nuclear reactions. Fission is the splitting of a heavy nucleus into lighter nuclei and fusion is the combining of nuclei to form a bigger and heavier nucleus. Fission and fusion are called nuclear reactions
[12] Acids on reacting with metal carbonates release which of the following gases?
A.
Hydrogen sulphide
B.
Carbon Dioxide
C.
Propane
D.
Hydrogen
Ans:
Carbon Dioxide
Explanation :
When an acid reacts with a metal carbonate, a salt, water and carbon dioxide are produced: Acid + metal carbonate → salt + water + carbon dioxide
[13] Which of the following is released during photosynthesis?
A.
Oxygen
B.
Carbon dioxide
C.
Energy
D.
Light
Ans:
Oxygen
Explanation :
Plants use photosynthesis as a way of producing glucose. They take in light energy from the sun and water and carbon dioxide from the air. This is then used to produce oxygen and glucose. 6CO2 + 6 H2O → C6H12O6 + 6O2
[14] Who discovered electron?
A.
E. Goldstien
B.
J. J. Thomson
C.
Ernest Rutherford
D.
J. Chadwick
Ans:
J. J. Thomson
Explanation :
J.J. Thomson is credited with the discovery and identification of the electron. Thomson, in 1897, was the first to suggest that one of the fundamental units was more than 1,000 times smaller than an atom, suggesting the sub atomic particle now known as the electron.
[15] Which of the following is also known as Carbolic Acid?
A.
Phenol
B.
Hydroxide
C.
Sulphuric Acid
D.
Ethanol
Ans:
Phenol
Explanation :
Phenol is also known as carbolic acid. It is an aromatic organic compound with the molecular formula C6H5OH. Phenol and its chemical derivatives are essential for production of polycarbonates, epoxies, Bakelite, nylon, detergents, herbicides such as phenoxy herbicides, and numerous pharmaceutical drugs.
[16] Galvanization of iron is carried out using –
A.
Zinc
B.
Tin
C.
Copper
D.
Chromium
Ans:
Zinc
Explanation :
Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. The term is derived from the name of Italian scientist Luigi Galvani. Although galvanization can be done with electrochemical and electrode position processes, the most common method in current use is hot-dip galvanization, in which steel parts are submerged in a bath of molten zinc.
[17] Cokking gas is a mixture of -
A.
methane and ethylene
B.
carbon dioxide and oxygen
C.
butane and propane
D.
carbon monoxide and carbon dioxide
Ans:
butane and propane
Explanation :
Liquefied petroleum gas, also called LPG, GPL, LP Gas, liquid petroleum gas or simply propane or butane, is a flammable mixture of hydrocarbon gases used as a fuel in heating appliances and vehicles. It is increasingly used as an aerosol propellant and a refrigerant, replacing chlorofluorocarbons in an effort to reduce damage to the ozone layer. When specifically used as a vehicle fuel it is often referred to as auto gas.
[18] The purest form of water is –
A.
tap water
B.
rain water
C.
ground water
D.
distilled water
Ans:
rain water
Explanation :
Rain is liquid water in the form of droplets that have condensed from atmospheric water vapor and then precipitated—that is, become heavy enough to fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides suitable conditions for many types of ecosystem, as well as water for hydroelectric power plants and crop irrigation. The major cause of rain production is moisture moving along three-dimensional zones of temperature and moisture contrasts known as weather fronts.
[19] The main constituent of biogas is –
A.
oxygen
B.
methane
C.
acetic acid
D.
methyl alcohol
Ans:
methane
Explanation :
Biogas typically refers to a gas produced by breakdown of organic matter in the absence of oxygen. Organic waste such as dead plant and animal material, animal feces, and kitchen waste can be converted into a gaseous fuel called biogas. Biogas originates from biogenic material and is a type of bio fuel. Biogas is produced by the anaerobic digestion or fermentation of biodegradable materials such as biomass, manure, sewage, municipal waste, green waste, plant material, and crops.
[20] Which metal is extracted from sea water?
A.
Potassium
B.
Magnesium
C.
Aluminium
D.
Beryllium
Ans:
Magnesium
Explanation :
The metal is now mainly obtained by electrolysis of magnesium salts obtained from brine. Commercially, the chief use for the metal is as an alloying agent to make aluminium-magnesium alloys, sometimes called "magnalium" or "magnelium". Since magnesium is less dense than aluminium, these alloys are prized for their relative lightness and strength. Magnesium is the fourth most common element in the Earth as a whole (behind iron, oxygen and silicon), making up 13% of the planet's mass and a large fraction of the planet's mantle.
[21] Percentage of lead in lead pencils is –
A.
0
B.
31-66
C.
40
D.
80
Ans:
0
Explanation :
There is no lead in pencils. Rather, the core is made up of non-toxic mineral called graphite. The common name "pencil lead" is due to an historic association with the stylus made of lead in ancient Roman times. Most pencil cores are made of graphite mixed with a clay binder, leaving grey or black marks that can be easily erased. Graphite pencils are used for both writing and drawing, and the result is durable: although writing can usually be removed with an eraser, it is resistant to moisture, most chemicals, ultraviolet radiation and natural aging.
[22] When formaldehyde and potassium hydroxide are heated, we get –
A.
Acetylene
B.
Methyl alcohol
C.
Methane
D.
Ethyl formate
Ans:
Methyl alcohol
Explanation :
When formaldehyde and potassium hydroxide are heated,we get methyl alcohol and formic acid. it is cannizarroo reaction. The Cannizzaro reaction, named after its discoverer StanislaoCannizzaro, is a chemical reaction that involves the base-induced disproportionation of an aldehyde. Cannizzaro first accomplished this transformation in 1853, when he obtained benzyl alcohol and potassium benzoate from the treatment of benzaldehyde with potash (potassium carbonate). More typically, the reaction would be conducted with sodium or potassium hydroxide. The oxidation product is a salt of a carboxylic acid and the reduction product is an alcohol.
[23] When conc. H2SO4 is added to diy KNO3, brown fumes are evolved. These fumes are due to –
A.
SO3
B.
SO2
C.
NO2
D.
N2O
Ans:
NO2
Explanation :
When concentrated hydrosulphuric acid is added to dry potassium nitrate brown fumes are evolved and these fumes are evolved due to the formation of nitrogen dioxide. Nitrogen dioxide is the chemical compound with the formula NO2. It is one of several nitrogen oxides. NO2 is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year. This reddish-brown toxic gas has a characteristic sharp, biting odour and is a prominent air pollutant. Nitrogen dioxide is a paramagnetic and bent molecule.
[24] Pasteurisation of milk means –
A.
heating of milk to above 72°C
B.
heating of milk to above 62°C
C.
cooling of milk to about 62°C
D.
cooling of milk to about 10°C
Ans:
heating of milk to above 62°C
Explanation :
Pasteurization typically uses temperatures below boiling, since at very high temperatures, casein micelles will irreversibly aggregate, or “curdle”. The two main types of pasteurization used today are: hightemperature, short-time (HTST) and “extended shelf life” (ESL) treatment. Ultra-high temperature (UHT or ultra-heat-treated) is also used for milk treatment. In the HTST process, milk is forced between metal plates or through pipes heated on the outside by hot water, and is heated to 71.7degree C (161degree F) for 15– 20 seconds. UHT processing holds the milk at a temperature of 135degree C (275degree F) for a minimum of one second. ESL milk has a microbial filtration step and lower temperatures than UHT milk. Milk simply labeled “pasteurized” is usually treated with the HTST method, whereas milk labeled “ultrapasteurized” or simply “UHT” has been treated with the UHT method. A less conventional but US FDAlegal alternative (typically for home pasteurization) is to heat milk at 145 degree F (63 degree C) for 30 minutes.
[25] Aluminium can be purified by –
A.
oxidation
B.
distillation
C.
electrolysis
D.
ozonolysis
Ans:
electrolysis
Explanation :
Electrolysis is a method of using a direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially highly important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell. Aluminum is extracted from its oxide ore “Bauxite”. Electrolytic smelting of alumina was originally cost-prohibitive in part because of the high melting point of alumina, or aluminium oxide. Many minerals, however, will dissolve into a second already molten mineral, even if the temperature of the melt is significantly lower than the melting point of the first mineral. Molten cryolite was discovered to dissolve alumina at temperatures significantly lower than the melting point of pure alumina without interfering in the smelting process.
Explanation :
The Bhopal disaster occurred on the night of 2-3 December 1984 at the Union Carbide India Limited (UCIL) pesticide plant in Bhopal, Madhya Pradesh. Over 500,000 people were exposed to methyl isocyanate has and other chemicals. The toxic substance made its way in and around the shantytowns located near the plant.
[10] The wine is prepared by the process of -
A.
fermentation
B.
catalysation
C.
conjugation
D.
displacement
Ans:
fermentation
Explanation :
After the destemmer the wine is pumped into tanks to begin fermentation. The process of fermentation in winemaking turns grape juice into an alcoholic beverage.
[11] Fission and fusion are called -
A.
molecular reactions
B.
potential reactions
C.
nuclear reactions
D.
heat reactions
Ans:
nuclear reactions
Explanation :
The energy harnessed in nuclei is released in nuclear reactions. Fission is the splitting of a heavy nucleus into lighter nuclei and fusion is the combining of nuclei to form a bigger and heavier nucleus. Fission and fusion are called nuclear reactions
[12] Acids on reacting with metal carbonates release which of the following gases?
A.
Hydrogen sulphide
B.
Carbon Dioxide
C.
Propane
D.
Hydrogen
Ans:
Carbon Dioxide
Explanation :
When an acid reacts with a metal carbonate, a salt, water and carbon dioxide are produced: Acid + metal carbonate → salt + water + carbon dioxide
[13] Which of the following is released during photosynthesis?
A.
Oxygen
B.
Carbon dioxide
C.
Energy
D.
Light
Ans:
Oxygen
Explanation :
Plants use photosynthesis as a way of producing glucose. They take in light energy from the sun and water and carbon dioxide from the air. This is then used to produce oxygen and glucose. 6CO2 + 6 H2O → C6H12O6 + 6O2
[14] Who discovered electron?
A.
E. Goldstien
B.
J. J. Thomson
C.
Ernest Rutherford
D.
J. Chadwick
Ans:
J. J. Thomson
Explanation :
J.J. Thomson is credited with the discovery and identification of the electron. Thomson, in 1897, was the first to suggest that one of the fundamental units was more than 1,000 times smaller than an atom, suggesting the sub atomic particle now known as the electron.
[15] Which of the following is also known as Carbolic Acid?
A.
Phenol
B.
Hydroxide
C.
Sulphuric Acid
D.
Ethanol
Ans:
Phenol
Explanation :
Phenol is also known as carbolic acid. It is an aromatic organic compound with the molecular formula C6H5OH. Phenol and its chemical derivatives are essential for production of polycarbonates, epoxies, Bakelite, nylon, detergents, herbicides such as phenoxy herbicides, and numerous pharmaceutical drugs.
[16] Galvanization of iron is carried out using –
A.
Zinc
B.
Tin
C.
Copper
D.
Chromium
Ans:
Zinc
Explanation :
Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. The term is derived from the name of Italian scientist Luigi Galvani. Although galvanization can be done with electrochemical and electrode position processes, the most common method in current use is hot-dip galvanization, in which steel parts are submerged in a bath of molten zinc.
[17] Cokking gas is a mixture of -
A.
methane and ethylene
B.
carbon dioxide and oxygen
C.
butane and propane
D.
carbon monoxide and carbon dioxide
Ans:
butane and propane
Explanation :
Liquefied petroleum gas, also called LPG, GPL, LP Gas, liquid petroleum gas or simply propane or butane, is a flammable mixture of hydrocarbon gases used as a fuel in heating appliances and vehicles. It is increasingly used as an aerosol propellant and a refrigerant, replacing chlorofluorocarbons in an effort to reduce damage to the ozone layer. When specifically used as a vehicle fuel it is often referred to as auto gas.
[18] The purest form of water is –
A.
tap water
B.
rain water
C.
ground water
D.
distilled water
Ans:
rain water
Explanation :
Rain is liquid water in the form of droplets that have condensed from atmospheric water vapor and then precipitated—that is, become heavy enough to fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides suitable conditions for many types of ecosystem, as well as water for hydroelectric power plants and crop irrigation. The major cause of rain production is moisture moving along three-dimensional zones of temperature and moisture contrasts known as weather fronts.
[19] The main constituent of biogas is –
A.
oxygen
B.
methane
C.
acetic acid
D.
methyl alcohol
Ans:
methane
Explanation :
Biogas typically refers to a gas produced by breakdown of organic matter in the absence of oxygen. Organic waste such as dead plant and animal material, animal feces, and kitchen waste can be converted into a gaseous fuel called biogas. Biogas originates from biogenic material and is a type of bio fuel. Biogas is produced by the anaerobic digestion or fermentation of biodegradable materials such as biomass, manure, sewage, municipal waste, green waste, plant material, and crops.
[20] Which metal is extracted from sea water?
A.
Potassium
B.
Magnesium
C.
Aluminium
D.
Beryllium
Ans:
Magnesium
Explanation :
The metal is now mainly obtained by electrolysis of magnesium salts obtained from brine. Commercially, the chief use for the metal is as an alloying agent to make aluminium-magnesium alloys, sometimes called "magnalium" or "magnelium". Since magnesium is less dense than aluminium, these alloys are prized for their relative lightness and strength. Magnesium is the fourth most common element in the Earth as a whole (behind iron, oxygen and silicon), making up 13% of the planet's mass and a large fraction of the planet's mantle.
[21] Percentage of lead in lead pencils is –
A.
0
B.
31-66
C.
40
D.
80
Ans:
0
Explanation :
There is no lead in pencils. Rather, the core is made up of non-toxic mineral called graphite. The common name "pencil lead" is due to an historic association with the stylus made of lead in ancient Roman times. Most pencil cores are made of graphite mixed with a clay binder, leaving grey or black marks that can be easily erased. Graphite pencils are used for both writing and drawing, and the result is durable: although writing can usually be removed with an eraser, it is resistant to moisture, most chemicals, ultraviolet radiation and natural aging.
[22] When formaldehyde and potassium hydroxide are heated, we get –
A.
Acetylene
B.
Methyl alcohol
C.
Methane
D.
Ethyl formate
Ans:
Methyl alcohol
Explanation :
When formaldehyde and potassium hydroxide are heated,we get methyl alcohol and formic acid. it is cannizarroo reaction. The Cannizzaro reaction, named after its discoverer StanislaoCannizzaro, is a chemical reaction that involves the base-induced disproportionation of an aldehyde. Cannizzaro first accomplished this transformation in 1853, when he obtained benzyl alcohol and potassium benzoate from the treatment of benzaldehyde with potash (potassium carbonate). More typically, the reaction would be conducted with sodium or potassium hydroxide. The oxidation product is a salt of a carboxylic acid and the reduction product is an alcohol.
[23] When conc. H2SO4 is added to diy KNO3, brown fumes are evolved. These fumes are due to –
A.
SO3
B.
SO2
C.
NO2
D.
N2O
Ans:
NO2
Explanation :
When concentrated hydrosulphuric acid is added to dry potassium nitrate brown fumes are evolved and these fumes are evolved due to the formation of nitrogen dioxide. Nitrogen dioxide is the chemical compound with the formula NO2. It is one of several nitrogen oxides. NO2 is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year. This reddish-brown toxic gas has a characteristic sharp, biting odour and is a prominent air pollutant. Nitrogen dioxide is a paramagnetic and bent molecule.
[24] Pasteurisation of milk means –
A.
heating of milk to above 72°C
B.
heating of milk to above 62°C
C.
cooling of milk to about 62°C
D.
cooling of milk to about 10°C
Ans:
heating of milk to above 62°C
Explanation :
Pasteurization typically uses temperatures below boiling, since at very high temperatures, casein micelles will irreversibly aggregate, or “curdle”. The two main types of pasteurization used today are: hightemperature, short-time (HTST) and “extended shelf life” (ESL) treatment. Ultra-high temperature (UHT or ultra-heat-treated) is also used for milk treatment. In the HTST process, milk is forced between metal plates or through pipes heated on the outside by hot water, and is heated to 71.7degree C (161degree F) for 15– 20 seconds. UHT processing holds the milk at a temperature of 135degree C (275degree F) for a minimum of one second. ESL milk has a microbial filtration step and lower temperatures than UHT milk. Milk simply labeled “pasteurized” is usually treated with the HTST method, whereas milk labeled “ultrapasteurized” or simply “UHT” has been treated with the UHT method. A less conventional but US FDAlegal alternative (typically for home pasteurization) is to heat milk at 145 degree F (63 degree C) for 30 minutes.
[25] Aluminium can be purified by –
A.
oxidation
B.
distillation
C.
electrolysis
D.
ozonolysis
Ans:
electrolysis
Explanation :
Electrolysis is a method of using a direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially highly important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell. Aluminum is extracted from its oxide ore “Bauxite”. Electrolytic smelting of alumina was originally cost-prohibitive in part because of the high melting point of alumina, or aluminium oxide. Many minerals, however, will dissolve into a second already molten mineral, even if the temperature of the melt is significantly lower than the melting point of the first mineral. Molten cryolite was discovered to dissolve alumina at temperatures significantly lower than the melting point of pure alumina without interfering in the smelting process.
Explanation :
The energy harnessed in nuclei is released in nuclear reactions. Fission is the splitting of a heavy nucleus into lighter nuclei and fusion is the combining of nuclei to form a bigger and heavier nucleus. Fission and fusion are called nuclear reactions
[12] Acids on reacting with metal carbonates release which of the following gases?
A.
Hydrogen sulphide
B.
Carbon Dioxide
C.
Propane
D.
Hydrogen
Ans:
Carbon Dioxide
Explanation :
When an acid reacts with a metal carbonate, a salt, water and carbon dioxide are produced: Acid + metal carbonate → salt + water + carbon dioxide
[13] Which of the following is released during photosynthesis?
A.
Oxygen
B.
Carbon dioxide
C.
Energy
D.
Light
Ans:
Oxygen
Explanation :
Plants use photosynthesis as a way of producing glucose. They take in light energy from the sun and water and carbon dioxide from the air. This is then used to produce oxygen and glucose. 6CO2 + 6 H2O → C6H12O6 + 6O2
[14] Who discovered electron?
A.
E. Goldstien
B.
J. J. Thomson
C.
Ernest Rutherford
D.
J. Chadwick
Ans:
J. J. Thomson
Explanation :
J.J. Thomson is credited with the discovery and identification of the electron. Thomson, in 1897, was the first to suggest that one of the fundamental units was more than 1,000 times smaller than an atom, suggesting the sub atomic particle now known as the electron.
[15] Which of the following is also known as Carbolic Acid?
A.
Phenol
B.
Hydroxide
C.
Sulphuric Acid
D.
Ethanol
Ans:
Phenol
Explanation :
Phenol is also known as carbolic acid. It is an aromatic organic compound with the molecular formula C6H5OH. Phenol and its chemical derivatives are essential for production of polycarbonates, epoxies, Bakelite, nylon, detergents, herbicides such as phenoxy herbicides, and numerous pharmaceutical drugs.
[16] Galvanization of iron is carried out using –
A.
Zinc
B.
Tin
C.
Copper
D.
Chromium
Ans:
Zinc
Explanation :
Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. The term is derived from the name of Italian scientist Luigi Galvani. Although galvanization can be done with electrochemical and electrode position processes, the most common method in current use is hot-dip galvanization, in which steel parts are submerged in a bath of molten zinc.
[17] Cokking gas is a mixture of -
A.
methane and ethylene
B.
carbon dioxide and oxygen
C.
butane and propane
D.
carbon monoxide and carbon dioxide
Ans:
butane and propane
Explanation :
Liquefied petroleum gas, also called LPG, GPL, LP Gas, liquid petroleum gas or simply propane or butane, is a flammable mixture of hydrocarbon gases used as a fuel in heating appliances and vehicles. It is increasingly used as an aerosol propellant and a refrigerant, replacing chlorofluorocarbons in an effort to reduce damage to the ozone layer. When specifically used as a vehicle fuel it is often referred to as auto gas.
[18] The purest form of water is –
A.
tap water
B.
rain water
C.
ground water
D.
distilled water
Ans:
rain water
Explanation :
Rain is liquid water in the form of droplets that have condensed from atmospheric water vapor and then precipitated—that is, become heavy enough to fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides suitable conditions for many types of ecosystem, as well as water for hydroelectric power plants and crop irrigation. The major cause of rain production is moisture moving along three-dimensional zones of temperature and moisture contrasts known as weather fronts.
[19] The main constituent of biogas is –
A.
oxygen
B.
methane
C.
acetic acid
D.
methyl alcohol
Ans:
methane
Explanation :
Biogas typically refers to a gas produced by breakdown of organic matter in the absence of oxygen. Organic waste such as dead plant and animal material, animal feces, and kitchen waste can be converted into a gaseous fuel called biogas. Biogas originates from biogenic material and is a type of bio fuel. Biogas is produced by the anaerobic digestion or fermentation of biodegradable materials such as biomass, manure, sewage, municipal waste, green waste, plant material, and crops.
[20] Which metal is extracted from sea water?
A.
Potassium
B.
Magnesium
C.
Aluminium
D.
Beryllium
Ans:
Magnesium
Explanation :
The metal is now mainly obtained by electrolysis of magnesium salts obtained from brine. Commercially, the chief use for the metal is as an alloying agent to make aluminium-magnesium alloys, sometimes called "magnalium" or "magnelium". Since magnesium is less dense than aluminium, these alloys are prized for their relative lightness and strength. Magnesium is the fourth most common element in the Earth as a whole (behind iron, oxygen and silicon), making up 13% of the planet's mass and a large fraction of the planet's mantle.
[21] Percentage of lead in lead pencils is –
A.
0
B.
31-66
C.
40
D.
80
Ans:
0
Explanation :
There is no lead in pencils. Rather, the core is made up of non-toxic mineral called graphite. The common name "pencil lead" is due to an historic association with the stylus made of lead in ancient Roman times. Most pencil cores are made of graphite mixed with a clay binder, leaving grey or black marks that can be easily erased. Graphite pencils are used for both writing and drawing, and the result is durable: although writing can usually be removed with an eraser, it is resistant to moisture, most chemicals, ultraviolet radiation and natural aging.
[22] When formaldehyde and potassium hydroxide are heated, we get –
A.
Acetylene
B.
Methyl alcohol
C.
Methane
D.
Ethyl formate
Ans:
Methyl alcohol
Explanation :
When formaldehyde and potassium hydroxide are heated,we get methyl alcohol and formic acid. it is cannizarroo reaction. The Cannizzaro reaction, named after its discoverer StanislaoCannizzaro, is a chemical reaction that involves the base-induced disproportionation of an aldehyde. Cannizzaro first accomplished this transformation in 1853, when he obtained benzyl alcohol and potassium benzoate from the treatment of benzaldehyde with potash (potassium carbonate). More typically, the reaction would be conducted with sodium or potassium hydroxide. The oxidation product is a salt of a carboxylic acid and the reduction product is an alcohol.
[23] When conc. H2SO4 is added to diy KNO3, brown fumes are evolved. These fumes are due to –
A.
SO3
B.
SO2
C.
NO2
D.
N2O
Ans:
NO2
Explanation :
When concentrated hydrosulphuric acid is added to dry potassium nitrate brown fumes are evolved and these fumes are evolved due to the formation of nitrogen dioxide. Nitrogen dioxide is the chemical compound with the formula NO2. It is one of several nitrogen oxides. NO2 is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year. This reddish-brown toxic gas has a characteristic sharp, biting odour and is a prominent air pollutant. Nitrogen dioxide is a paramagnetic and bent molecule.
[24] Pasteurisation of milk means –
A.
heating of milk to above 72°C
B.
heating of milk to above 62°C
C.
cooling of milk to about 62°C
D.
cooling of milk to about 10°C
Ans:
heating of milk to above 62°C
Explanation :
Pasteurization typically uses temperatures below boiling, since at very high temperatures, casein micelles will irreversibly aggregate, or “curdle”. The two main types of pasteurization used today are: hightemperature, short-time (HTST) and “extended shelf life” (ESL) treatment. Ultra-high temperature (UHT or ultra-heat-treated) is also used for milk treatment. In the HTST process, milk is forced between metal plates or through pipes heated on the outside by hot water, and is heated to 71.7degree C (161degree F) for 15– 20 seconds. UHT processing holds the milk at a temperature of 135degree C (275degree F) for a minimum of one second. ESL milk has a microbial filtration step and lower temperatures than UHT milk. Milk simply labeled “pasteurized” is usually treated with the HTST method, whereas milk labeled “ultrapasteurized” or simply “UHT” has been treated with the UHT method. A less conventional but US FDAlegal alternative (typically for home pasteurization) is to heat milk at 145 degree F (63 degree C) for 30 minutes.
[25] Aluminium can be purified by –
A.
oxidation
B.
distillation
C.
electrolysis
D.
ozonolysis
Ans:
electrolysis
Explanation :
Electrolysis is a method of using a direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially highly important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell. Aluminum is extracted from its oxide ore “Bauxite”. Electrolytic smelting of alumina was originally cost-prohibitive in part because of the high melting point of alumina, or aluminium oxide. Many minerals, however, will dissolve into a second already molten mineral, even if the temperature of the melt is significantly lower than the melting point of the first mineral. Molten cryolite was discovered to dissolve alumina at temperatures significantly lower than the melting point of pure alumina without interfering in the smelting process.
Explanation :
Plants use photosynthesis as a way of producing glucose. They take in light energy from the sun and water and carbon dioxide from the air. This is then used to produce oxygen and glucose. 6CO2 + 6 H2O → C6H12O6 + 6O2
[14] Who discovered electron?
A.
E. Goldstien
B.
J. J. Thomson
C.
Ernest Rutherford
D.
J. Chadwick
Ans:
J. J. Thomson
Explanation :
J.J. Thomson is credited with the discovery and identification of the electron. Thomson, in 1897, was the first to suggest that one of the fundamental units was more than 1,000 times smaller than an atom, suggesting the sub atomic particle now known as the electron.
[15] Which of the following is also known as Carbolic Acid?
A.
Phenol
B.
Hydroxide
C.
Sulphuric Acid
D.
Ethanol
Ans:
Phenol
Explanation :
Phenol is also known as carbolic acid. It is an aromatic organic compound with the molecular formula C6H5OH. Phenol and its chemical derivatives are essential for production of polycarbonates, epoxies, Bakelite, nylon, detergents, herbicides such as phenoxy herbicides, and numerous pharmaceutical drugs.
[16] Galvanization of iron is carried out using –
A.
Zinc
B.
Tin
C.
Copper
D.
Chromium
Ans:
Zinc
Explanation :
Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. The term is derived from the name of Italian scientist Luigi Galvani. Although galvanization can be done with electrochemical and electrode position processes, the most common method in current use is hot-dip galvanization, in which steel parts are submerged in a bath of molten zinc.
[17] Cokking gas is a mixture of -
A.
methane and ethylene
B.
carbon dioxide and oxygen
C.
butane and propane
D.
carbon monoxide and carbon dioxide
Ans:
butane and propane
Explanation :
Liquefied petroleum gas, also called LPG, GPL, LP Gas, liquid petroleum gas or simply propane or butane, is a flammable mixture of hydrocarbon gases used as a fuel in heating appliances and vehicles. It is increasingly used as an aerosol propellant and a refrigerant, replacing chlorofluorocarbons in an effort to reduce damage to the ozone layer. When specifically used as a vehicle fuel it is often referred to as auto gas.
[18] The purest form of water is –
A.
tap water
B.
rain water
C.
ground water
D.
distilled water
Ans:
rain water
Explanation :
Rain is liquid water in the form of droplets that have condensed from atmospheric water vapor and then precipitated—that is, become heavy enough to fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides suitable conditions for many types of ecosystem, as well as water for hydroelectric power plants and crop irrigation. The major cause of rain production is moisture moving along three-dimensional zones of temperature and moisture contrasts known as weather fronts.
[19] The main constituent of biogas is –
A.
oxygen
B.
methane
C.
acetic acid
D.
methyl alcohol
Ans:
methane
Explanation :
Biogas typically refers to a gas produced by breakdown of organic matter in the absence of oxygen. Organic waste such as dead plant and animal material, animal feces, and kitchen waste can be converted into a gaseous fuel called biogas. Biogas originates from biogenic material and is a type of bio fuel. Biogas is produced by the anaerobic digestion or fermentation of biodegradable materials such as biomass, manure, sewage, municipal waste, green waste, plant material, and crops.
[20] Which metal is extracted from sea water?
A.
Potassium
B.
Magnesium
C.
Aluminium
D.
Beryllium
Ans:
Magnesium
Explanation :
The metal is now mainly obtained by electrolysis of magnesium salts obtained from brine. Commercially, the chief use for the metal is as an alloying agent to make aluminium-magnesium alloys, sometimes called "magnalium" or "magnelium". Since magnesium is less dense than aluminium, these alloys are prized for their relative lightness and strength. Magnesium is the fourth most common element in the Earth as a whole (behind iron, oxygen and silicon), making up 13% of the planet's mass and a large fraction of the planet's mantle.
[21] Percentage of lead in lead pencils is –
A.
0
B.
31-66
C.
40
D.
80
Ans:
0
Explanation :
There is no lead in pencils. Rather, the core is made up of non-toxic mineral called graphite. The common name "pencil lead" is due to an historic association with the stylus made of lead in ancient Roman times. Most pencil cores are made of graphite mixed with a clay binder, leaving grey or black marks that can be easily erased. Graphite pencils are used for both writing and drawing, and the result is durable: although writing can usually be removed with an eraser, it is resistant to moisture, most chemicals, ultraviolet radiation and natural aging.
[22] When formaldehyde and potassium hydroxide are heated, we get –
A.
Acetylene
B.
Methyl alcohol
C.
Methane
D.
Ethyl formate
Ans:
Methyl alcohol
Explanation :
When formaldehyde and potassium hydroxide are heated,we get methyl alcohol and formic acid. it is cannizarroo reaction. The Cannizzaro reaction, named after its discoverer StanislaoCannizzaro, is a chemical reaction that involves the base-induced disproportionation of an aldehyde. Cannizzaro first accomplished this transformation in 1853, when he obtained benzyl alcohol and potassium benzoate from the treatment of benzaldehyde with potash (potassium carbonate). More typically, the reaction would be conducted with sodium or potassium hydroxide. The oxidation product is a salt of a carboxylic acid and the reduction product is an alcohol.
[23] When conc. H2SO4 is added to diy KNO3, brown fumes are evolved. These fumes are due to –
A.
SO3
B.
SO2
C.
NO2
D.
N2O
Ans:
NO2
Explanation :
When concentrated hydrosulphuric acid is added to dry potassium nitrate brown fumes are evolved and these fumes are evolved due to the formation of nitrogen dioxide. Nitrogen dioxide is the chemical compound with the formula NO2. It is one of several nitrogen oxides. NO2 is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year. This reddish-brown toxic gas has a characteristic sharp, biting odour and is a prominent air pollutant. Nitrogen dioxide is a paramagnetic and bent molecule.
[24] Pasteurisation of milk means –
A.
heating of milk to above 72°C
B.
heating of milk to above 62°C
C.
cooling of milk to about 62°C
D.
cooling of milk to about 10°C
Ans:
heating of milk to above 62°C
Explanation :
Pasteurization typically uses temperatures below boiling, since at very high temperatures, casein micelles will irreversibly aggregate, or “curdle”. The two main types of pasteurization used today are: hightemperature, short-time (HTST) and “extended shelf life” (ESL) treatment. Ultra-high temperature (UHT or ultra-heat-treated) is also used for milk treatment. In the HTST process, milk is forced between metal plates or through pipes heated on the outside by hot water, and is heated to 71.7degree C (161degree F) for 15– 20 seconds. UHT processing holds the milk at a temperature of 135degree C (275degree F) for a minimum of one second. ESL milk has a microbial filtration step and lower temperatures than UHT milk. Milk simply labeled “pasteurized” is usually treated with the HTST method, whereas milk labeled “ultrapasteurized” or simply “UHT” has been treated with the UHT method. A less conventional but US FDAlegal alternative (typically for home pasteurization) is to heat milk at 145 degree F (63 degree C) for 30 minutes.
[25] Aluminium can be purified by –
A.
oxidation
B.
distillation
C.
electrolysis
D.
ozonolysis
Ans:
electrolysis
Explanation :
Electrolysis is a method of using a direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially highly important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell. Aluminum is extracted from its oxide ore “Bauxite”. Electrolytic smelting of alumina was originally cost-prohibitive in part because of the high melting point of alumina, or aluminium oxide. Many minerals, however, will dissolve into a second already molten mineral, even if the temperature of the melt is significantly lower than the melting point of the first mineral. Molten cryolite was discovered to dissolve alumina at temperatures significantly lower than the melting point of pure alumina without interfering in the smelting process.
Explanation :
Phenol is also known as carbolic acid. It is an aromatic organic compound with the molecular formula C6H5OH. Phenol and its chemical derivatives are essential for production of polycarbonates, epoxies, Bakelite, nylon, detergents, herbicides such as phenoxy herbicides, and numerous pharmaceutical drugs.
[16] Galvanization of iron is carried out using –
A.
Zinc
B.
Tin
C.
Copper
D.
Chromium
Ans:
Zinc
Explanation :
Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. The term is derived from the name of Italian scientist Luigi Galvani. Although galvanization can be done with electrochemical and electrode position processes, the most common method in current use is hot-dip galvanization, in which steel parts are submerged in a bath of molten zinc.
[17] Cokking gas is a mixture of -
A.
methane and ethylene
B.
carbon dioxide and oxygen
C.
butane and propane
D.
carbon monoxide and carbon dioxide
Ans:
butane and propane
Explanation :
Liquefied petroleum gas, also called LPG, GPL, LP Gas, liquid petroleum gas or simply propane or butane, is a flammable mixture of hydrocarbon gases used as a fuel in heating appliances and vehicles. It is increasingly used as an aerosol propellant and a refrigerant, replacing chlorofluorocarbons in an effort to reduce damage to the ozone layer. When specifically used as a vehicle fuel it is often referred to as auto gas.
[18] The purest form of water is –
A.
tap water
B.
rain water
C.
ground water
D.
distilled water
Ans:
rain water
Explanation :
Rain is liquid water in the form of droplets that have condensed from atmospheric water vapor and then precipitated—that is, become heavy enough to fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides suitable conditions for many types of ecosystem, as well as water for hydroelectric power plants and crop irrigation. The major cause of rain production is moisture moving along three-dimensional zones of temperature and moisture contrasts known as weather fronts.
[19] The main constituent of biogas is –
A.
oxygen
B.
methane
C.
acetic acid
D.
methyl alcohol
Ans:
methane
Explanation :
Biogas typically refers to a gas produced by breakdown of organic matter in the absence of oxygen. Organic waste such as dead plant and animal material, animal feces, and kitchen waste can be converted into a gaseous fuel called biogas. Biogas originates from biogenic material and is a type of bio fuel. Biogas is produced by the anaerobic digestion or fermentation of biodegradable materials such as biomass, manure, sewage, municipal waste, green waste, plant material, and crops.
[20] Which metal is extracted from sea water?
A.
Potassium
B.
Magnesium
C.
Aluminium
D.
Beryllium
Ans:
Magnesium
Explanation :
The metal is now mainly obtained by electrolysis of magnesium salts obtained from brine. Commercially, the chief use for the metal is as an alloying agent to make aluminium-magnesium alloys, sometimes called "magnalium" or "magnelium". Since magnesium is less dense than aluminium, these alloys are prized for their relative lightness and strength. Magnesium is the fourth most common element in the Earth as a whole (behind iron, oxygen and silicon), making up 13% of the planet's mass and a large fraction of the planet's mantle.
[21] Percentage of lead in lead pencils is –
A.
0
B.
31-66
C.
40
D.
80
Ans:
0
Explanation :
There is no lead in pencils. Rather, the core is made up of non-toxic mineral called graphite. The common name "pencil lead" is due to an historic association with the stylus made of lead in ancient Roman times. Most pencil cores are made of graphite mixed with a clay binder, leaving grey or black marks that can be easily erased. Graphite pencils are used for both writing and drawing, and the result is durable: although writing can usually be removed with an eraser, it is resistant to moisture, most chemicals, ultraviolet radiation and natural aging.
[22] When formaldehyde and potassium hydroxide are heated, we get –
A.
Acetylene
B.
Methyl alcohol
C.
Methane
D.
Ethyl formate
Ans:
Methyl alcohol
Explanation :
When formaldehyde and potassium hydroxide are heated,we get methyl alcohol and formic acid. it is cannizarroo reaction. The Cannizzaro reaction, named after its discoverer StanislaoCannizzaro, is a chemical reaction that involves the base-induced disproportionation of an aldehyde. Cannizzaro first accomplished this transformation in 1853, when he obtained benzyl alcohol and potassium benzoate from the treatment of benzaldehyde with potash (potassium carbonate). More typically, the reaction would be conducted with sodium or potassium hydroxide. The oxidation product is a salt of a carboxylic acid and the reduction product is an alcohol.
[23] When conc. H2SO4 is added to diy KNO3, brown fumes are evolved. These fumes are due to –
A.
SO3
B.
SO2
C.
NO2
D.
N2O
Ans:
NO2
Explanation :
When concentrated hydrosulphuric acid is added to dry potassium nitrate brown fumes are evolved and these fumes are evolved due to the formation of nitrogen dioxide. Nitrogen dioxide is the chemical compound with the formula NO2. It is one of several nitrogen oxides. NO2 is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year. This reddish-brown toxic gas has a characteristic sharp, biting odour and is a prominent air pollutant. Nitrogen dioxide is a paramagnetic and bent molecule.
[24] Pasteurisation of milk means –
A.
heating of milk to above 72°C
B.
heating of milk to above 62°C
C.
cooling of milk to about 62°C
D.
cooling of milk to about 10°C
Ans:
heating of milk to above 62°C
Explanation :
Pasteurization typically uses temperatures below boiling, since at very high temperatures, casein micelles will irreversibly aggregate, or “curdle”. The two main types of pasteurization used today are: hightemperature, short-time (HTST) and “extended shelf life” (ESL) treatment. Ultra-high temperature (UHT or ultra-heat-treated) is also used for milk treatment. In the HTST process, milk is forced between metal plates or through pipes heated on the outside by hot water, and is heated to 71.7degree C (161degree F) for 15– 20 seconds. UHT processing holds the milk at a temperature of 135degree C (275degree F) for a minimum of one second. ESL milk has a microbial filtration step and lower temperatures than UHT milk. Milk simply labeled “pasteurized” is usually treated with the HTST method, whereas milk labeled “ultrapasteurized” or simply “UHT” has been treated with the UHT method. A less conventional but US FDAlegal alternative (typically for home pasteurization) is to heat milk at 145 degree F (63 degree C) for 30 minutes.
[25] Aluminium can be purified by –
A.
oxidation
B.
distillation
C.
electrolysis
D.
ozonolysis
Ans:
electrolysis
Explanation :
Electrolysis is a method of using a direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially highly important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell. Aluminum is extracted from its oxide ore “Bauxite”. Electrolytic smelting of alumina was originally cost-prohibitive in part because of the high melting point of alumina, or aluminium oxide. Many minerals, however, will dissolve into a second already molten mineral, even if the temperature of the melt is significantly lower than the melting point of the first mineral. Molten cryolite was discovered to dissolve alumina at temperatures significantly lower than the melting point of pure alumina without interfering in the smelting process.
Explanation :
Liquefied petroleum gas, also called LPG, GPL, LP Gas, liquid petroleum gas or simply propane or butane, is a flammable mixture of hydrocarbon gases used as a fuel in heating appliances and vehicles. It is increasingly used as an aerosol propellant and a refrigerant, replacing chlorofluorocarbons in an effort to reduce damage to the ozone layer. When specifically used as a vehicle fuel it is often referred to as auto gas.
[18] The purest form of water is –
A.
tap water
B.
rain water
C.
ground water
D.
distilled water
Ans:
rain water
Explanation :
Rain is liquid water in the form of droplets that have condensed from atmospheric water vapor and then precipitated—that is, become heavy enough to fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides suitable conditions for many types of ecosystem, as well as water for hydroelectric power plants and crop irrigation. The major cause of rain production is moisture moving along three-dimensional zones of temperature and moisture contrasts known as weather fronts.
[19] The main constituent of biogas is –
A.
oxygen
B.
methane
C.
acetic acid
D.
methyl alcohol
Ans:
methane
Explanation :
Biogas typically refers to a gas produced by breakdown of organic matter in the absence of oxygen. Organic waste such as dead plant and animal material, animal feces, and kitchen waste can be converted into a gaseous fuel called biogas. Biogas originates from biogenic material and is a type of bio fuel. Biogas is produced by the anaerobic digestion or fermentation of biodegradable materials such as biomass, manure, sewage, municipal waste, green waste, plant material, and crops.
[20] Which metal is extracted from sea water?
A.
Potassium
B.
Magnesium
C.
Aluminium
D.
Beryllium
Ans:
Magnesium
Explanation :
The metal is now mainly obtained by electrolysis of magnesium salts obtained from brine. Commercially, the chief use for the metal is as an alloying agent to make aluminium-magnesium alloys, sometimes called "magnalium" or "magnelium". Since magnesium is less dense than aluminium, these alloys are prized for their relative lightness and strength. Magnesium is the fourth most common element in the Earth as a whole (behind iron, oxygen and silicon), making up 13% of the planet's mass and a large fraction of the planet's mantle.
[21] Percentage of lead in lead pencils is –
A.
0
B.
31-66
C.
40
D.
80
Ans:
0
Explanation :
There is no lead in pencils. Rather, the core is made up of non-toxic mineral called graphite. The common name "pencil lead" is due to an historic association with the stylus made of lead in ancient Roman times. Most pencil cores are made of graphite mixed with a clay binder, leaving grey or black marks that can be easily erased. Graphite pencils are used for both writing and drawing, and the result is durable: although writing can usually be removed with an eraser, it is resistant to moisture, most chemicals, ultraviolet radiation and natural aging.
[22] When formaldehyde and potassium hydroxide are heated, we get –
A.
Acetylene
B.
Methyl alcohol
C.
Methane
D.
Ethyl formate
Ans:
Methyl alcohol
Explanation :
When formaldehyde and potassium hydroxide are heated,we get methyl alcohol and formic acid. it is cannizarroo reaction. The Cannizzaro reaction, named after its discoverer StanislaoCannizzaro, is a chemical reaction that involves the base-induced disproportionation of an aldehyde. Cannizzaro first accomplished this transformation in 1853, when he obtained benzyl alcohol and potassium benzoate from the treatment of benzaldehyde with potash (potassium carbonate). More typically, the reaction would be conducted with sodium or potassium hydroxide. The oxidation product is a salt of a carboxylic acid and the reduction product is an alcohol.
[23] When conc. H2SO4 is added to diy KNO3, brown fumes are evolved. These fumes are due to –
A.
SO3
B.
SO2
C.
NO2
D.
N2O
Ans:
NO2
Explanation :
When concentrated hydrosulphuric acid is added to dry potassium nitrate brown fumes are evolved and these fumes are evolved due to the formation of nitrogen dioxide. Nitrogen dioxide is the chemical compound with the formula NO2. It is one of several nitrogen oxides. NO2 is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year. This reddish-brown toxic gas has a characteristic sharp, biting odour and is a prominent air pollutant. Nitrogen dioxide is a paramagnetic and bent molecule.
[24] Pasteurisation of milk means –
A.
heating of milk to above 72°C
B.
heating of milk to above 62°C
C.
cooling of milk to about 62°C
D.
cooling of milk to about 10°C
Ans:
heating of milk to above 62°C
Explanation :
Pasteurization typically uses temperatures below boiling, since at very high temperatures, casein micelles will irreversibly aggregate, or “curdle”. The two main types of pasteurization used today are: hightemperature, short-time (HTST) and “extended shelf life” (ESL) treatment. Ultra-high temperature (UHT or ultra-heat-treated) is also used for milk treatment. In the HTST process, milk is forced between metal plates or through pipes heated on the outside by hot water, and is heated to 71.7degree C (161degree F) for 15– 20 seconds. UHT processing holds the milk at a temperature of 135degree C (275degree F) for a minimum of one second. ESL milk has a microbial filtration step and lower temperatures than UHT milk. Milk simply labeled “pasteurized” is usually treated with the HTST method, whereas milk labeled “ultrapasteurized” or simply “UHT” has been treated with the UHT method. A less conventional but US FDAlegal alternative (typically for home pasteurization) is to heat milk at 145 degree F (63 degree C) for 30 minutes.
[25] Aluminium can be purified by –
A.
oxidation
B.
distillation
C.
electrolysis
D.
ozonolysis
Ans:
electrolysis
Explanation :
Electrolysis is a method of using a direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially highly important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell. Aluminum is extracted from its oxide ore “Bauxite”. Electrolytic smelting of alumina was originally cost-prohibitive in part because of the high melting point of alumina, or aluminium oxide. Many minerals, however, will dissolve into a second already molten mineral, even if the temperature of the melt is significantly lower than the melting point of the first mineral. Molten cryolite was discovered to dissolve alumina at temperatures significantly lower than the melting point of pure alumina without interfering in the smelting process.
Explanation :
Biogas typically refers to a gas produced by breakdown of organic matter in the absence of oxygen. Organic waste such as dead plant and animal material, animal feces, and kitchen waste can be converted into a gaseous fuel called biogas. Biogas originates from biogenic material and is a type of bio fuel. Biogas is produced by the anaerobic digestion or fermentation of biodegradable materials such as biomass, manure, sewage, municipal waste, green waste, plant material, and crops.
[20] Which metal is extracted from sea water?
A.
Potassium
B.
Magnesium
C.
Aluminium
D.
Beryllium
Ans:
Magnesium
Explanation :
The metal is now mainly obtained by electrolysis of magnesium salts obtained from brine. Commercially, the chief use for the metal is as an alloying agent to make aluminium-magnesium alloys, sometimes called "magnalium" or "magnelium". Since magnesium is less dense than aluminium, these alloys are prized for their relative lightness and strength. Magnesium is the fourth most common element in the Earth as a whole (behind iron, oxygen and silicon), making up 13% of the planet's mass and a large fraction of the planet's mantle.
[21] Percentage of lead in lead pencils is –
A.
0
B.
31-66
C.
40
D.
80
Ans:
0
Explanation :
There is no lead in pencils. Rather, the core is made up of non-toxic mineral called graphite. The common name "pencil lead" is due to an historic association with the stylus made of lead in ancient Roman times. Most pencil cores are made of graphite mixed with a clay binder, leaving grey or black marks that can be easily erased. Graphite pencils are used for both writing and drawing, and the result is durable: although writing can usually be removed with an eraser, it is resistant to moisture, most chemicals, ultraviolet radiation and natural aging.
[22] When formaldehyde and potassium hydroxide are heated, we get –
A.
Acetylene
B.
Methyl alcohol
C.
Methane
D.
Ethyl formate
Ans:
Methyl alcohol
Explanation :
When formaldehyde and potassium hydroxide are heated,we get methyl alcohol and formic acid. it is cannizarroo reaction. The Cannizzaro reaction, named after its discoverer StanislaoCannizzaro, is a chemical reaction that involves the base-induced disproportionation of an aldehyde. Cannizzaro first accomplished this transformation in 1853, when he obtained benzyl alcohol and potassium benzoate from the treatment of benzaldehyde with potash (potassium carbonate). More typically, the reaction would be conducted with sodium or potassium hydroxide. The oxidation product is a salt of a carboxylic acid and the reduction product is an alcohol.
[23] When conc. H2SO4 is added to diy KNO3, brown fumes are evolved. These fumes are due to –
A.
SO3
B.
SO2
C.
NO2
D.
N2O
Ans:
NO2
Explanation :
When concentrated hydrosulphuric acid is added to dry potassium nitrate brown fumes are evolved and these fumes are evolved due to the formation of nitrogen dioxide. Nitrogen dioxide is the chemical compound with the formula NO2. It is one of several nitrogen oxides. NO2 is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year. This reddish-brown toxic gas has a characteristic sharp, biting odour and is a prominent air pollutant. Nitrogen dioxide is a paramagnetic and bent molecule.
[24] Pasteurisation of milk means –
A.
heating of milk to above 72°C
B.
heating of milk to above 62°C
C.
cooling of milk to about 62°C
D.
cooling of milk to about 10°C
Ans:
heating of milk to above 62°C
Explanation :
Pasteurization typically uses temperatures below boiling, since at very high temperatures, casein micelles will irreversibly aggregate, or “curdle”. The two main types of pasteurization used today are: hightemperature, short-time (HTST) and “extended shelf life” (ESL) treatment. Ultra-high temperature (UHT or ultra-heat-treated) is also used for milk treatment. In the HTST process, milk is forced between metal plates or through pipes heated on the outside by hot water, and is heated to 71.7degree C (161degree F) for 15– 20 seconds. UHT processing holds the milk at a temperature of 135degree C (275degree F) for a minimum of one second. ESL milk has a microbial filtration step and lower temperatures than UHT milk. Milk simply labeled “pasteurized” is usually treated with the HTST method, whereas milk labeled “ultrapasteurized” or simply “UHT” has been treated with the UHT method. A less conventional but US FDAlegal alternative (typically for home pasteurization) is to heat milk at 145 degree F (63 degree C) for 30 minutes.
[25] Aluminium can be purified by –
A.
oxidation
B.
distillation
C.
electrolysis
D.
ozonolysis
Ans:
electrolysis
Explanation :
Electrolysis is a method of using a direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially highly important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell. Aluminum is extracted from its oxide ore “Bauxite”. Electrolytic smelting of alumina was originally cost-prohibitive in part because of the high melting point of alumina, or aluminium oxide. Many minerals, however, will dissolve into a second already molten mineral, even if the temperature of the melt is significantly lower than the melting point of the first mineral. Molten cryolite was discovered to dissolve alumina at temperatures significantly lower than the melting point of pure alumina without interfering in the smelting process.
Explanation :
There is no lead in pencils. Rather, the core is made up of non-toxic mineral called graphite. The common name "pencil lead" is due to an historic association with the stylus made of lead in ancient Roman times. Most pencil cores are made of graphite mixed with a clay binder, leaving grey or black marks that can be easily erased. Graphite pencils are used for both writing and drawing, and the result is durable: although writing can usually be removed with an eraser, it is resistant to moisture, most chemicals, ultraviolet radiation and natural aging.
[22] When formaldehyde and potassium hydroxide are heated, we get –
A.
Acetylene
B.
Methyl alcohol
C.
Methane
D.
Ethyl formate
Ans:
Methyl alcohol
Explanation :
When formaldehyde and potassium hydroxide are heated,we get methyl alcohol and formic acid. it is cannizarroo reaction. The Cannizzaro reaction, named after its discoverer StanislaoCannizzaro, is a chemical reaction that involves the base-induced disproportionation of an aldehyde. Cannizzaro first accomplished this transformation in 1853, when he obtained benzyl alcohol and potassium benzoate from the treatment of benzaldehyde with potash (potassium carbonate). More typically, the reaction would be conducted with sodium or potassium hydroxide. The oxidation product is a salt of a carboxylic acid and the reduction product is an alcohol.
[23] When conc. H2SO4 is added to diy KNO3, brown fumes are evolved. These fumes are due to –
A.
SO3
B.
SO2
C.
NO2
D.
N2O
Ans:
NO2
Explanation :
When concentrated hydrosulphuric acid is added to dry potassium nitrate brown fumes are evolved and these fumes are evolved due to the formation of nitrogen dioxide. Nitrogen dioxide is the chemical compound with the formula NO2. It is one of several nitrogen oxides. NO2 is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year. This reddish-brown toxic gas has a characteristic sharp, biting odour and is a prominent air pollutant. Nitrogen dioxide is a paramagnetic and bent molecule.
[24] Pasteurisation of milk means –
A.
heating of milk to above 72°C
B.
heating of milk to above 62°C
C.
cooling of milk to about 62°C
D.
cooling of milk to about 10°C
Ans:
heating of milk to above 62°C
Explanation :
Pasteurization typically uses temperatures below boiling, since at very high temperatures, casein micelles will irreversibly aggregate, or “curdle”. The two main types of pasteurization used today are: hightemperature, short-time (HTST) and “extended shelf life” (ESL) treatment. Ultra-high temperature (UHT or ultra-heat-treated) is also used for milk treatment. In the HTST process, milk is forced between metal plates or through pipes heated on the outside by hot water, and is heated to 71.7degree C (161degree F) for 15– 20 seconds. UHT processing holds the milk at a temperature of 135degree C (275degree F) for a minimum of one second. ESL milk has a microbial filtration step and lower temperatures than UHT milk. Milk simply labeled “pasteurized” is usually treated with the HTST method, whereas milk labeled “ultrapasteurized” or simply “UHT” has been treated with the UHT method. A less conventional but US FDAlegal alternative (typically for home pasteurization) is to heat milk at 145 degree F (63 degree C) for 30 minutes.
[25] Aluminium can be purified by –
A.
oxidation
B.
distillation
C.
electrolysis
D.
ozonolysis
Ans:
electrolysis
Explanation :
Electrolysis is a method of using a direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially highly important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell. Aluminum is extracted from its oxide ore “Bauxite”. Electrolytic smelting of alumina was originally cost-prohibitive in part because of the high melting point of alumina, or aluminium oxide. Many minerals, however, will dissolve into a second already molten mineral, even if the temperature of the melt is significantly lower than the melting point of the first mineral. Molten cryolite was discovered to dissolve alumina at temperatures significantly lower than the melting point of pure alumina without interfering in the smelting process.
Explanation :
When concentrated hydrosulphuric acid is added to dry potassium nitrate brown fumes are evolved and these fumes are evolved due to the formation of nitrogen dioxide. Nitrogen dioxide is the chemical compound with the formula NO2. It is one of several nitrogen oxides. NO2 is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year. This reddish-brown toxic gas has a characteristic sharp, biting odour and is a prominent air pollutant. Nitrogen dioxide is a paramagnetic and bent molecule.
[24] Pasteurisation of milk means –
A.
heating of milk to above 72°C
B.
heating of milk to above 62°C
C.
cooling of milk to about 62°C
D.
cooling of milk to about 10°C
Ans:
heating of milk to above 62°C
Explanation :
Pasteurization typically uses temperatures below boiling, since at very high temperatures, casein micelles will irreversibly aggregate, or “curdle”. The two main types of pasteurization used today are: hightemperature, short-time (HTST) and “extended shelf life” (ESL) treatment. Ultra-high temperature (UHT or ultra-heat-treated) is also used for milk treatment. In the HTST process, milk is forced between metal plates or through pipes heated on the outside by hot water, and is heated to 71.7degree C (161degree F) for 15– 20 seconds. UHT processing holds the milk at a temperature of 135degree C (275degree F) for a minimum of one second. ESL milk has a microbial filtration step and lower temperatures than UHT milk. Milk simply labeled “pasteurized” is usually treated with the HTST method, whereas milk labeled “ultrapasteurized” or simply “UHT” has been treated with the UHT method. A less conventional but US FDAlegal alternative (typically for home pasteurization) is to heat milk at 145 degree F (63 degree C) for 30 minutes.
[25] Aluminium can be purified by –
A.
oxidation
B.
distillation
C.
electrolysis
D.
ozonolysis
Ans:
electrolysis
Explanation :
Electrolysis is a method of using a direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially highly important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell. Aluminum is extracted from its oxide ore “Bauxite”. Electrolytic smelting of alumina was originally cost-prohibitive in part because of the high melting point of alumina, or aluminium oxide. Many minerals, however, will dissolve into a second already molten mineral, even if the temperature of the melt is significantly lower than the melting point of the first mineral. Molten cryolite was discovered to dissolve alumina at temperatures significantly lower than the melting point of pure alumina without interfering in the smelting process.
Explanation :
Electrolysis is a method of using a direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially highly important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell. Aluminum is extracted from its oxide ore “Bauxite”. Electrolytic smelting of alumina was originally cost-prohibitive in part because of the high melting point of alumina, or aluminium oxide. Many minerals, however, will dissolve into a second already molten mineral, even if the temperature of the melt is significantly lower than the melting point of the first mineral. Molten cryolite was discovered to dissolve alumina at temperatures significantly lower than the melting point of pure alumina without interfering in the smelting process.