[1] The metal used in storage batteries-
A.
Iron
B.
Copper
C.
Lead
D.
Zinc
Ans:
Lead
Explanation :
Commercially available batteries use a variety of metals and electrolytes. Anodes can be made of zinc, aluminum, lithium, cadmium, iron, metallic lead, lanthanide, or graphite
[2] Type metal used in printing press is an alloy of -
A.
lead and copper
B.
lead and antimony
C.
lead and bismuth
D.
lead and zinc
Ans:
lead and antimony
Explanation :
Lead and antimony are used to make type metals alloy. These type metals are used to make the character produced durable and tough.
[3] The acid which is secreted by the glands in the stomach wall is –
A.
sulphuric acid
B.
hydrochloric acid
C.
nitric acid
D.
phosphoric acid
Ans:
hydrochloric acid
Explanation :
Gastric acid is a digestive fluid, formed in the stomach. It has a pH of 1.5 to 3.5 and is composed of hydrochloric acid (HCl) (around 0.5%, or 5000 parts per million), and large quantities of potassium chloride (KCl) and sodium chloride (NaCl). The acid plays a key role in digestion of proteins, by activating digestive enzymes, and making ingested proteins unravel so that digestive enzymes can break down the long chains of amino acids.
[4] Dry ice is –
A.
solid ammonia
B.
solid sulphur dioxide
C.
dry carbon dioxide gas
D.
solid carbon dioxide
Ans:
solid carbon dioxide
Explanation :
Dry ice is the solid form of carbon dioxide. It is used primarily as a cooling agent. Its advantages include lower temperature than that of water ice and not leaving any residue. It is useful for preserving frozen foods, ice cream, etc., where mechanical cooling is unavailable.
[5] Cement containing excess amount of lime –
A.
cracks during setting
B.
becomes more strong
C.
is slow setting
D.
is quick setting
Ans:
cracks during setting
Explanation :
In cement almost entire amount of lime is present in combined state as calcium silicates and calcium aluminates. Cement containing excess amount of lime cracks during setting while cement containing less amount of lime is weak in strength. Setting of cement is an exothermic process.
[6] Which one of the following is a micro-element?
A.
Chlorine
B.
Hydrogen
C.
Nitrogen
D.
Oxygen
Ans:
Chlorine
Explanation :
In analytical chemistry, a trace element or micro-element is an element in a sample that has an average concentration of less than 100 parts per million measured in atomic count or less than 100 micrograms per gram. These are those elements essential for plant growth which are needed in only very small (micro). They are: boron (B), copper (Cu), iron (Fe), chloride (Cl), manganese (Mn), molybdenum (Mo) and zinc (Zn).
[7] In vulcanization, natural rubber is heated with-
A.
Carbon
B.
Sulphur
C.
Silicon
D.
Phosphorus
Ans:
Sulphur
Explanation :
Vulcanization of rubber is a process of improvement of the rubber elasticity and strength by heating it in the presence of sulfur, which results in three-dimensional cross-linking of the chain rubber molecules (polyisoprene) bonded to each other by sulfur atoms.
[8] An example of major air pollutant is –
A.
Oxygen
B.
Carbon monoxide
C.
Helium
D.
Carbon dioxide
Ans:
Carbon monoxide
Explanation :
Carbon monoxide (CO) is a colourless, odorless, non-irritating but very poisonous gas which is a product by incomplete combustion of fuel such as natural gas, coal or wood. Vehicular exhaust is a major source of carbon monoxide.
[9] The metal, used to galvanise iron to protect it from rusting is -
A.
Zine
B.
Chromium
C.
Lead
D.
Antimony
Ans:
Zine
Explanation :
Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. Although galvanization can be done with electrochemical and electro-deposition processes, the most common method in current use is hot-dip galvanization, in which steel parts are submerged in a bath of molten zinc.
[10] Which of the following gases is mixed with oxygen for breathing by divers in aqualungs?
A.
Methane
B.
Nitrogen
C.
Helium
D.
Hydrogen
Ans:
Nitrogen
Explanation :
For some diving, has mixtures other than normal atmospheric air (21 % oxygen, 78% nitrogen, 1% trace gases) can be used, so long as the diver is properly trained in their use. The most commonly used mixture is Nitrox, also referred to as Enriched Air Nitrox (EAN), which is air with extra oxygen, often with 32% or 36% oxygen, and thus less nitrogen, reducing the likelihood of decompression sickness or allowing longer exposure to the same pressure for equal risk.
[11] The material known in commerce as Terylene is a –
A.
Synthetic fibre
B.
Natural fibre
C.
Modified natural fibre
D.
Blend of cotton and silk
Ans:
Synthetic fibre
Explanation :
Terylene is the name for a synthetic polyester fibre. It is a synthetic polyester fibre or fabric based on terephthalic acid, characterized by lightness and crease resistance and used for clothing, sheets, ropes, sails, etc.
[12] Among the fuels given below, the one with highest calorific value is –
A.
Coke
B.
Coal
C.
Wood
D.
Natural gas
Ans:
Natural gas
Explanation :
The calorific values of different fuels (in Kcal/kg) in dry state are: Wood: 3500; Coal: 4000-7000; Coke: 6500; and Natural Gas: 8600 Kcal/kg.
[13] Electric bulbs are filled with –
A.
Nitrogen
B.
Carbon dioxide
C.
Argon
D.
Oxygen
Ans:
Argon
Explanation :
Argon is produced industrially by the fractional distillation of liquid air. Argon is mostly used as an inert shielding has in welding and other high-temperature industrial processes where ordinarily non-reactive substances become reactive; for example, an argon atmosphere is used in graphite electric furnaces to prevent the graphite from burning. Argon bas also has uses in incandescent and fluorescent lighting, and other types of gas discharge tubes. Argon makes a distinctive blue-green gas laser.
[14] The purest form of Iron is :
A.
Cast iron
B.
Steel
C.
Pig iron
D.
Wrought iron
Ans:
Wrought iron
Explanation :
Wrought iron is an iron alloy with a very low carbon content in Contrast to steel, and has fibrous inclusions, known as slag. This is what gives it a "grain" resembling wood, which is visible when it is etched or bent to the point of failure. Wrought iron is tough, malleable, ductile and easily welded. Historically, it was known as "commercially pure iron"; however, it no longer qualifies because current standards for commercially pure iron require a carbon content of less than 0.008 wt%.
[15] Which of the following metals are present in hemoglobin and chlorophyll, respectively?
A.
Fe and Mg
B.
Fe and Zn
C.
Mg and Zn
D.
Zn and Mg
Ans:
Fe and Mg
Explanation :
Fe and Mg metals are present in hemoglobin and Chlorophyll respectively.
[16] Atomic mass of Nitrogen is 14 and that of Hydrogen is 1. What will be the molecular mass of Ammonia?
A.
18
B.
17
C.
16
D.
15
Ans:
17
Explanation :
Ammonia (NH3) is composed of one atom of Nitrogen and three Hydrogen atoms. This means that its molar mass of ammonia will be the sum of the molar mass of one nitrogen atom and three times the molar mass of a hydrogen atom.
[17] Silver halides are used in photographic plates because they are -
A.
oxidised in air
B.
soluble in hyposolution
C.
reduced by light
D.
totally colourless
Ans:
reduced by light
Explanation :
The light-sensitive chemicals used in photographic film and paper are silver halides. Silver halides are used in photographic film and photographic paper, including graphic art film and paper, where silver halide crystals in gelatin are coated on to a film base, glass or paper substrate. When a silver halide crystal is exposed to light, a sensitivity speck on the surface of the crystal is turned into a small speck of metallic silver (these comprise the invisible or latent image). If the speck of silver contains approximately four or more atoms, it is rendered developable - meaning that it can undergo development which turns the entire crystal into metallic silver.
[18] Tetra ethyle lead (TEL) is -
A.
a catalyst in burning fossil fuel
B.
an antioxidant
C.
areductant
D.
an antiknock compound
Ans:
an antiknock compound
Explanation :
Tetraethyl lead was extensively used as an additive to gasoline, wherein it served as an effective antiknock agent and prevented exhaust valve and seat wear. The use of TEL in gasoline started in the US, while in Europe, alcohol was initially used. The advantages of leaded gasoline — its higher enemy content and storage quality —eventually led to a universal switch to leaded fuel. One of the greatest advantages of TEL over other antiknock agents or the use of high-octane blend stocks is the very low concentrations needed. Typical formulations called for 1 part of prepared TEL to 1260 parts untreated gasoline.
[19] Which metal is heaviest -
A.
osmium
B.
mercury
C.
iron
D.
nickel
Ans:
osmium
Explanation :
I assume by "heaviest," you mean "densest;" in that case, the densest chemical element is osmium (which is a metal). Osmium has a density of around 22 grams per cubic centimeter.
[20] The term PVC used in the plastic industry stands for -
A.
polyvinyl chloride
B.
polyvinyl carbonate
C.
phosphor vanadium chloride
D.
phosphavinyl chloride
Ans:
polyvinyl chloride
Explanation :
Polyvinyl chloride is the world's third-most widely produced synthetic plastic polymer, after polyethylene and polypropylene. About 40 million tones are produced per year.
[21] Rusting of iron takes place due to –
A.
oxidation
B.
carbonation
C.
exfoliation
D.
corrosion
Ans:
oxidation
Explanation :
The rusting of iron is an electrochemical process that begins with the transfer of electrons from iron to oxygen. The rate of corrosion is affected by water and accelerated by electrolytes, as illustrated by the effects of road salt on the corrosion of automobiles. When impure (cast) iron is in contact with water, oxygen, or other strong oxidants, or acids, it rusts.
[22] German silver used for making utensils is an alloy of –
A.
Copper, silver, nickel
B.
Copper, zinc, nickel
C.
copper, zinc, aluminium
D.
copper, nickel, aluminium
Ans:
Copper, zinc, nickel
Explanation :
Nickel silver, also known as German silver, Argentan, new silver, nickel brass, albata, alpacca, or electrum, is a copper alloy with nickel and often zinc. The usual formulation is 60% copper, 20% nickel and 20% zinc. Nickel silver is named for its silvery appearance, but it contains no elemental silver unless plated. The name "German silver" refers to its development by 19th-century German metalworkers in imitation of the Chinese alloy known as paktong.
[23] Sour milk contains –
A.
acetic acid
B.
tartaric acid
C.
citric acid
D.
lactic acid
Ans:
lactic acid
Explanation :
Lactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3. Lactic acid is found primarily in sour milk products, such as koumiss, laban, yogurt, kefir, and some cottage cheeses. The casein in fermented milk is coagulated (curdled) by lactic acid.
[24] The acid used in lead storage cells is –
A.
phosphoric acid
B.
hydrochloric acid
C.
nitric acid
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Lead-acid batteries, invented in 1859 by French physicist Gaston Plante, are the oldest type of rechargeable battery. Despite having a very low energy-to-weight ratio and a low energy-to-volume ratio, their ability to supply high surge currents means that the cells maintain a relatively large power- to-weight ratio. These features, along with their low cost, make them attractive for use in motor vehicles to provide the high current required by automobile starter motors.
[25] Milk is an example of -
A.
suspension
B.
true solution
C.
emulsion
D.
gel
Ans:
emulsion
Explanation :
An emulsion is a mixture of two or more liquids that are normally immiscible (nonmixable or unblendable). Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion should be used when both the dispersed and the continuous phase are liquids. In an emulsion, one liquid (the dispersed phase) is dispersed in the other (the continuous phase). Examples of emulsions include vinaigrettes, milk, mayonnaise, and some cutting fluids for metal working. The photo-sensitive side of photographic film is also an example of a colloid. The word “emulsion” comes from the Latin word for “to milk”, as milk is (among other things) an emulsion of milk fat and water.
Explanation :
Commercially available batteries use a variety of metals and electrolytes. Anodes can be made of zinc, aluminum, lithium, cadmium, iron, metallic lead, lanthanide, or graphite
[2] Type metal used in printing press is an alloy of -
A.
lead and copper
B.
lead and antimony
C.
lead and bismuth
D.
lead and zinc
Ans:
lead and antimony
Explanation :
Lead and antimony are used to make type metals alloy. These type metals are used to make the character produced durable and tough.
[3] The acid which is secreted by the glands in the stomach wall is –
A.
sulphuric acid
B.
hydrochloric acid
C.
nitric acid
D.
phosphoric acid
Ans:
hydrochloric acid
Explanation :
Gastric acid is a digestive fluid, formed in the stomach. It has a pH of 1.5 to 3.5 and is composed of hydrochloric acid (HCl) (around 0.5%, or 5000 parts per million), and large quantities of potassium chloride (KCl) and sodium chloride (NaCl). The acid plays a key role in digestion of proteins, by activating digestive enzymes, and making ingested proteins unravel so that digestive enzymes can break down the long chains of amino acids.
[4] Dry ice is –
A.
solid ammonia
B.
solid sulphur dioxide
C.
dry carbon dioxide gas
D.
solid carbon dioxide
Ans:
solid carbon dioxide
Explanation :
Dry ice is the solid form of carbon dioxide. It is used primarily as a cooling agent. Its advantages include lower temperature than that of water ice and not leaving any residue. It is useful for preserving frozen foods, ice cream, etc., where mechanical cooling is unavailable.
[5] Cement containing excess amount of lime –
A.
cracks during setting
B.
becomes more strong
C.
is slow setting
D.
is quick setting
Ans:
cracks during setting
Explanation :
In cement almost entire amount of lime is present in combined state as calcium silicates and calcium aluminates. Cement containing excess amount of lime cracks during setting while cement containing less amount of lime is weak in strength. Setting of cement is an exothermic process.
[6] Which one of the following is a micro-element?
A.
Chlorine
B.
Hydrogen
C.
Nitrogen
D.
Oxygen
Ans:
Chlorine
Explanation :
In analytical chemistry, a trace element or micro-element is an element in a sample that has an average concentration of less than 100 parts per million measured in atomic count or less than 100 micrograms per gram. These are those elements essential for plant growth which are needed in only very small (micro). They are: boron (B), copper (Cu), iron (Fe), chloride (Cl), manganese (Mn), molybdenum (Mo) and zinc (Zn).
[7] In vulcanization, natural rubber is heated with-
A.
Carbon
B.
Sulphur
C.
Silicon
D.
Phosphorus
Ans:
Sulphur
Explanation :
Vulcanization of rubber is a process of improvement of the rubber elasticity and strength by heating it in the presence of sulfur, which results in three-dimensional cross-linking of the chain rubber molecules (polyisoprene) bonded to each other by sulfur atoms.
[8] An example of major air pollutant is –
A.
Oxygen
B.
Carbon monoxide
C.
Helium
D.
Carbon dioxide
Ans:
Carbon monoxide
Explanation :
Carbon monoxide (CO) is a colourless, odorless, non-irritating but very poisonous gas which is a product by incomplete combustion of fuel such as natural gas, coal or wood. Vehicular exhaust is a major source of carbon monoxide.
[9] The metal, used to galvanise iron to protect it from rusting is -
A.
Zine
B.
Chromium
C.
Lead
D.
Antimony
Ans:
Zine
Explanation :
Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. Although galvanization can be done with electrochemical and electro-deposition processes, the most common method in current use is hot-dip galvanization, in which steel parts are submerged in a bath of molten zinc.
[10] Which of the following gases is mixed with oxygen for breathing by divers in aqualungs?
A.
Methane
B.
Nitrogen
C.
Helium
D.
Hydrogen
Ans:
Nitrogen
Explanation :
For some diving, has mixtures other than normal atmospheric air (21 % oxygen, 78% nitrogen, 1% trace gases) can be used, so long as the diver is properly trained in their use. The most commonly used mixture is Nitrox, also referred to as Enriched Air Nitrox (EAN), which is air with extra oxygen, often with 32% or 36% oxygen, and thus less nitrogen, reducing the likelihood of decompression sickness or allowing longer exposure to the same pressure for equal risk.
[11] The material known in commerce as Terylene is a –
A.
Synthetic fibre
B.
Natural fibre
C.
Modified natural fibre
D.
Blend of cotton and silk
Ans:
Synthetic fibre
Explanation :
Terylene is the name for a synthetic polyester fibre. It is a synthetic polyester fibre or fabric based on terephthalic acid, characterized by lightness and crease resistance and used for clothing, sheets, ropes, sails, etc.
[12] Among the fuels given below, the one with highest calorific value is –
A.
Coke
B.
Coal
C.
Wood
D.
Natural gas
Ans:
Natural gas
Explanation :
The calorific values of different fuels (in Kcal/kg) in dry state are: Wood: 3500; Coal: 4000-7000; Coke: 6500; and Natural Gas: 8600 Kcal/kg.
[13] Electric bulbs are filled with –
A.
Nitrogen
B.
Carbon dioxide
C.
Argon
D.
Oxygen
Ans:
Argon
Explanation :
Argon is produced industrially by the fractional distillation of liquid air. Argon is mostly used as an inert shielding has in welding and other high-temperature industrial processes where ordinarily non-reactive substances become reactive; for example, an argon atmosphere is used in graphite electric furnaces to prevent the graphite from burning. Argon bas also has uses in incandescent and fluorescent lighting, and other types of gas discharge tubes. Argon makes a distinctive blue-green gas laser.
[14] The purest form of Iron is :
A.
Cast iron
B.
Steel
C.
Pig iron
D.
Wrought iron
Ans:
Wrought iron
Explanation :
Wrought iron is an iron alloy with a very low carbon content in Contrast to steel, and has fibrous inclusions, known as slag. This is what gives it a "grain" resembling wood, which is visible when it is etched or bent to the point of failure. Wrought iron is tough, malleable, ductile and easily welded. Historically, it was known as "commercially pure iron"; however, it no longer qualifies because current standards for commercially pure iron require a carbon content of less than 0.008 wt%.
[15] Which of the following metals are present in hemoglobin and chlorophyll, respectively?
A.
Fe and Mg
B.
Fe and Zn
C.
Mg and Zn
D.
Zn and Mg
Ans:
Fe and Mg
Explanation :
Fe and Mg metals are present in hemoglobin and Chlorophyll respectively.
[16] Atomic mass of Nitrogen is 14 and that of Hydrogen is 1. What will be the molecular mass of Ammonia?
A.
18
B.
17
C.
16
D.
15
Ans:
17
Explanation :
Ammonia (NH3) is composed of one atom of Nitrogen and three Hydrogen atoms. This means that its molar mass of ammonia will be the sum of the molar mass of one nitrogen atom and three times the molar mass of a hydrogen atom.
[17] Silver halides are used in photographic plates because they are -
A.
oxidised in air
B.
soluble in hyposolution
C.
reduced by light
D.
totally colourless
Ans:
reduced by light
Explanation :
The light-sensitive chemicals used in photographic film and paper are silver halides. Silver halides are used in photographic film and photographic paper, including graphic art film and paper, where silver halide crystals in gelatin are coated on to a film base, glass or paper substrate. When a silver halide crystal is exposed to light, a sensitivity speck on the surface of the crystal is turned into a small speck of metallic silver (these comprise the invisible or latent image). If the speck of silver contains approximately four or more atoms, it is rendered developable - meaning that it can undergo development which turns the entire crystal into metallic silver.
[18] Tetra ethyle lead (TEL) is -
A.
a catalyst in burning fossil fuel
B.
an antioxidant
C.
areductant
D.
an antiknock compound
Ans:
an antiknock compound
Explanation :
Tetraethyl lead was extensively used as an additive to gasoline, wherein it served as an effective antiknock agent and prevented exhaust valve and seat wear. The use of TEL in gasoline started in the US, while in Europe, alcohol was initially used. The advantages of leaded gasoline — its higher enemy content and storage quality —eventually led to a universal switch to leaded fuel. One of the greatest advantages of TEL over other antiknock agents or the use of high-octane blend stocks is the very low concentrations needed. Typical formulations called for 1 part of prepared TEL to 1260 parts untreated gasoline.
[19] Which metal is heaviest -
A.
osmium
B.
mercury
C.
iron
D.
nickel
Ans:
osmium
Explanation :
I assume by "heaviest," you mean "densest;" in that case, the densest chemical element is osmium (which is a metal). Osmium has a density of around 22 grams per cubic centimeter.
[20] The term PVC used in the plastic industry stands for -
A.
polyvinyl chloride
B.
polyvinyl carbonate
C.
phosphor vanadium chloride
D.
phosphavinyl chloride
Ans:
polyvinyl chloride
Explanation :
Polyvinyl chloride is the world's third-most widely produced synthetic plastic polymer, after polyethylene and polypropylene. About 40 million tones are produced per year.
[21] Rusting of iron takes place due to –
A.
oxidation
B.
carbonation
C.
exfoliation
D.
corrosion
Ans:
oxidation
Explanation :
The rusting of iron is an electrochemical process that begins with the transfer of electrons from iron to oxygen. The rate of corrosion is affected by water and accelerated by electrolytes, as illustrated by the effects of road salt on the corrosion of automobiles. When impure (cast) iron is in contact with water, oxygen, or other strong oxidants, or acids, it rusts.
[22] German silver used for making utensils is an alloy of –
A.
Copper, silver, nickel
B.
Copper, zinc, nickel
C.
copper, zinc, aluminium
D.
copper, nickel, aluminium
Ans:
Copper, zinc, nickel
Explanation :
Nickel silver, also known as German silver, Argentan, new silver, nickel brass, albata, alpacca, or electrum, is a copper alloy with nickel and often zinc. The usual formulation is 60% copper, 20% nickel and 20% zinc. Nickel silver is named for its silvery appearance, but it contains no elemental silver unless plated. The name "German silver" refers to its development by 19th-century German metalworkers in imitation of the Chinese alloy known as paktong.
[23] Sour milk contains –
A.
acetic acid
B.
tartaric acid
C.
citric acid
D.
lactic acid
Ans:
lactic acid
Explanation :
Lactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3. Lactic acid is found primarily in sour milk products, such as koumiss, laban, yogurt, kefir, and some cottage cheeses. The casein in fermented milk is coagulated (curdled) by lactic acid.
[24] The acid used in lead storage cells is –
A.
phosphoric acid
B.
hydrochloric acid
C.
nitric acid
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Lead-acid batteries, invented in 1859 by French physicist Gaston Plante, are the oldest type of rechargeable battery. Despite having a very low energy-to-weight ratio and a low energy-to-volume ratio, their ability to supply high surge currents means that the cells maintain a relatively large power- to-weight ratio. These features, along with their low cost, make them attractive for use in motor vehicles to provide the high current required by automobile starter motors.
[25] Milk is an example of -
A.
suspension
B.
true solution
C.
emulsion
D.
gel
Ans:
emulsion
Explanation :
An emulsion is a mixture of two or more liquids that are normally immiscible (nonmixable or unblendable). Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion should be used when both the dispersed and the continuous phase are liquids. In an emulsion, one liquid (the dispersed phase) is dispersed in the other (the continuous phase). Examples of emulsions include vinaigrettes, milk, mayonnaise, and some cutting fluids for metal working. The photo-sensitive side of photographic film is also an example of a colloid. The word “emulsion” comes from the Latin word for “to milk”, as milk is (among other things) an emulsion of milk fat and water.
Explanation :
Gastric acid is a digestive fluid, formed in the stomach. It has a pH of 1.5 to 3.5 and is composed of hydrochloric acid (HCl) (around 0.5%, or 5000 parts per million), and large quantities of potassium chloride (KCl) and sodium chloride (NaCl). The acid plays a key role in digestion of proteins, by activating digestive enzymes, and making ingested proteins unravel so that digestive enzymes can break down the long chains of amino acids.
[4] Dry ice is –
A.
solid ammonia
B.
solid sulphur dioxide
C.
dry carbon dioxide gas
D.
solid carbon dioxide
Ans:
solid carbon dioxide
Explanation :
Dry ice is the solid form of carbon dioxide. It is used primarily as a cooling agent. Its advantages include lower temperature than that of water ice and not leaving any residue. It is useful for preserving frozen foods, ice cream, etc., where mechanical cooling is unavailable.
[5] Cement containing excess amount of lime –
A.
cracks during setting
B.
becomes more strong
C.
is slow setting
D.
is quick setting
Ans:
cracks during setting
Explanation :
In cement almost entire amount of lime is present in combined state as calcium silicates and calcium aluminates. Cement containing excess amount of lime cracks during setting while cement containing less amount of lime is weak in strength. Setting of cement is an exothermic process.
[6] Which one of the following is a micro-element?
A.
Chlorine
B.
Hydrogen
C.
Nitrogen
D.
Oxygen
Ans:
Chlorine
Explanation :
In analytical chemistry, a trace element or micro-element is an element in a sample that has an average concentration of less than 100 parts per million measured in atomic count or less than 100 micrograms per gram. These are those elements essential for plant growth which are needed in only very small (micro). They are: boron (B), copper (Cu), iron (Fe), chloride (Cl), manganese (Mn), molybdenum (Mo) and zinc (Zn).
[7] In vulcanization, natural rubber is heated with-
A.
Carbon
B.
Sulphur
C.
Silicon
D.
Phosphorus
Ans:
Sulphur
Explanation :
Vulcanization of rubber is a process of improvement of the rubber elasticity and strength by heating it in the presence of sulfur, which results in three-dimensional cross-linking of the chain rubber molecules (polyisoprene) bonded to each other by sulfur atoms.
[8] An example of major air pollutant is –
A.
Oxygen
B.
Carbon monoxide
C.
Helium
D.
Carbon dioxide
Ans:
Carbon monoxide
Explanation :
Carbon monoxide (CO) is a colourless, odorless, non-irritating but very poisonous gas which is a product by incomplete combustion of fuel such as natural gas, coal or wood. Vehicular exhaust is a major source of carbon monoxide.
[9] The metal, used to galvanise iron to protect it from rusting is -
A.
Zine
B.
Chromium
C.
Lead
D.
Antimony
Ans:
Zine
Explanation :
Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. Although galvanization can be done with electrochemical and electro-deposition processes, the most common method in current use is hot-dip galvanization, in which steel parts are submerged in a bath of molten zinc.
[10] Which of the following gases is mixed with oxygen for breathing by divers in aqualungs?
A.
Methane
B.
Nitrogen
C.
Helium
D.
Hydrogen
Ans:
Nitrogen
Explanation :
For some diving, has mixtures other than normal atmospheric air (21 % oxygen, 78% nitrogen, 1% trace gases) can be used, so long as the diver is properly trained in their use. The most commonly used mixture is Nitrox, also referred to as Enriched Air Nitrox (EAN), which is air with extra oxygen, often with 32% or 36% oxygen, and thus less nitrogen, reducing the likelihood of decompression sickness or allowing longer exposure to the same pressure for equal risk.
[11] The material known in commerce as Terylene is a –
A.
Synthetic fibre
B.
Natural fibre
C.
Modified natural fibre
D.
Blend of cotton and silk
Ans:
Synthetic fibre
Explanation :
Terylene is the name for a synthetic polyester fibre. It is a synthetic polyester fibre or fabric based on terephthalic acid, characterized by lightness and crease resistance and used for clothing, sheets, ropes, sails, etc.
[12] Among the fuels given below, the one with highest calorific value is –
A.
Coke
B.
Coal
C.
Wood
D.
Natural gas
Ans:
Natural gas
Explanation :
The calorific values of different fuels (in Kcal/kg) in dry state are: Wood: 3500; Coal: 4000-7000; Coke: 6500; and Natural Gas: 8600 Kcal/kg.
[13] Electric bulbs are filled with –
A.
Nitrogen
B.
Carbon dioxide
C.
Argon
D.
Oxygen
Ans:
Argon
Explanation :
Argon is produced industrially by the fractional distillation of liquid air. Argon is mostly used as an inert shielding has in welding and other high-temperature industrial processes where ordinarily non-reactive substances become reactive; for example, an argon atmosphere is used in graphite electric furnaces to prevent the graphite from burning. Argon bas also has uses in incandescent and fluorescent lighting, and other types of gas discharge tubes. Argon makes a distinctive blue-green gas laser.
[14] The purest form of Iron is :
A.
Cast iron
B.
Steel
C.
Pig iron
D.
Wrought iron
Ans:
Wrought iron
Explanation :
Wrought iron is an iron alloy with a very low carbon content in Contrast to steel, and has fibrous inclusions, known as slag. This is what gives it a "grain" resembling wood, which is visible when it is etched or bent to the point of failure. Wrought iron is tough, malleable, ductile and easily welded. Historically, it was known as "commercially pure iron"; however, it no longer qualifies because current standards for commercially pure iron require a carbon content of less than 0.008 wt%.
[15] Which of the following metals are present in hemoglobin and chlorophyll, respectively?
A.
Fe and Mg
B.
Fe and Zn
C.
Mg and Zn
D.
Zn and Mg
Ans:
Fe and Mg
Explanation :
Fe and Mg metals are present in hemoglobin and Chlorophyll respectively.
[16] Atomic mass of Nitrogen is 14 and that of Hydrogen is 1. What will be the molecular mass of Ammonia?
A.
18
B.
17
C.
16
D.
15
Ans:
17
Explanation :
Ammonia (NH3) is composed of one atom of Nitrogen and three Hydrogen atoms. This means that its molar mass of ammonia will be the sum of the molar mass of one nitrogen atom and three times the molar mass of a hydrogen atom.
[17] Silver halides are used in photographic plates because they are -
A.
oxidised in air
B.
soluble in hyposolution
C.
reduced by light
D.
totally colourless
Ans:
reduced by light
Explanation :
The light-sensitive chemicals used in photographic film and paper are silver halides. Silver halides are used in photographic film and photographic paper, including graphic art film and paper, where silver halide crystals in gelatin are coated on to a film base, glass or paper substrate. When a silver halide crystal is exposed to light, a sensitivity speck on the surface of the crystal is turned into a small speck of metallic silver (these comprise the invisible or latent image). If the speck of silver contains approximately four or more atoms, it is rendered developable - meaning that it can undergo development which turns the entire crystal into metallic silver.
[18] Tetra ethyle lead (TEL) is -
A.
a catalyst in burning fossil fuel
B.
an antioxidant
C.
areductant
D.
an antiknock compound
Ans:
an antiknock compound
Explanation :
Tetraethyl lead was extensively used as an additive to gasoline, wherein it served as an effective antiknock agent and prevented exhaust valve and seat wear. The use of TEL in gasoline started in the US, while in Europe, alcohol was initially used. The advantages of leaded gasoline — its higher enemy content and storage quality —eventually led to a universal switch to leaded fuel. One of the greatest advantages of TEL over other antiknock agents or the use of high-octane blend stocks is the very low concentrations needed. Typical formulations called for 1 part of prepared TEL to 1260 parts untreated gasoline.
[19] Which metal is heaviest -
A.
osmium
B.
mercury
C.
iron
D.
nickel
Ans:
osmium
Explanation :
I assume by "heaviest," you mean "densest;" in that case, the densest chemical element is osmium (which is a metal). Osmium has a density of around 22 grams per cubic centimeter.
[20] The term PVC used in the plastic industry stands for -
A.
polyvinyl chloride
B.
polyvinyl carbonate
C.
phosphor vanadium chloride
D.
phosphavinyl chloride
Ans:
polyvinyl chloride
Explanation :
Polyvinyl chloride is the world's third-most widely produced synthetic plastic polymer, after polyethylene and polypropylene. About 40 million tones are produced per year.
[21] Rusting of iron takes place due to –
A.
oxidation
B.
carbonation
C.
exfoliation
D.
corrosion
Ans:
oxidation
Explanation :
The rusting of iron is an electrochemical process that begins with the transfer of electrons from iron to oxygen. The rate of corrosion is affected by water and accelerated by electrolytes, as illustrated by the effects of road salt on the corrosion of automobiles. When impure (cast) iron is in contact with water, oxygen, or other strong oxidants, or acids, it rusts.
[22] German silver used for making utensils is an alloy of –
A.
Copper, silver, nickel
B.
Copper, zinc, nickel
C.
copper, zinc, aluminium
D.
copper, nickel, aluminium
Ans:
Copper, zinc, nickel
Explanation :
Nickel silver, also known as German silver, Argentan, new silver, nickel brass, albata, alpacca, or electrum, is a copper alloy with nickel and often zinc. The usual formulation is 60% copper, 20% nickel and 20% zinc. Nickel silver is named for its silvery appearance, but it contains no elemental silver unless plated. The name "German silver" refers to its development by 19th-century German metalworkers in imitation of the Chinese alloy known as paktong.
[23] Sour milk contains –
A.
acetic acid
B.
tartaric acid
C.
citric acid
D.
lactic acid
Ans:
lactic acid
Explanation :
Lactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3. Lactic acid is found primarily in sour milk products, such as koumiss, laban, yogurt, kefir, and some cottage cheeses. The casein in fermented milk is coagulated (curdled) by lactic acid.
[24] The acid used in lead storage cells is –
A.
phosphoric acid
B.
hydrochloric acid
C.
nitric acid
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Lead-acid batteries, invented in 1859 by French physicist Gaston Plante, are the oldest type of rechargeable battery. Despite having a very low energy-to-weight ratio and a low energy-to-volume ratio, their ability to supply high surge currents means that the cells maintain a relatively large power- to-weight ratio. These features, along with their low cost, make them attractive for use in motor vehicles to provide the high current required by automobile starter motors.
[25] Milk is an example of -
A.
suspension
B.
true solution
C.
emulsion
D.
gel
Ans:
emulsion
Explanation :
An emulsion is a mixture of two or more liquids that are normally immiscible (nonmixable or unblendable). Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion should be used when both the dispersed and the continuous phase are liquids. In an emulsion, one liquid (the dispersed phase) is dispersed in the other (the continuous phase). Examples of emulsions include vinaigrettes, milk, mayonnaise, and some cutting fluids for metal working. The photo-sensitive side of photographic film is also an example of a colloid. The word “emulsion” comes from the Latin word for “to milk”, as milk is (among other things) an emulsion of milk fat and water.
Explanation :
In cement almost entire amount of lime is present in combined state as calcium silicates and calcium aluminates. Cement containing excess amount of lime cracks during setting while cement containing less amount of lime is weak in strength. Setting of cement is an exothermic process.
[6] Which one of the following is a micro-element?
A.
Chlorine
B.
Hydrogen
C.
Nitrogen
D.
Oxygen
Ans:
Chlorine
Explanation :
In analytical chemistry, a trace element or micro-element is an element in a sample that has an average concentration of less than 100 parts per million measured in atomic count or less than 100 micrograms per gram. These are those elements essential for plant growth which are needed in only very small (micro). They are: boron (B), copper (Cu), iron (Fe), chloride (Cl), manganese (Mn), molybdenum (Mo) and zinc (Zn).
[7] In vulcanization, natural rubber is heated with-
A.
Carbon
B.
Sulphur
C.
Silicon
D.
Phosphorus
Ans:
Sulphur
Explanation :
Vulcanization of rubber is a process of improvement of the rubber elasticity and strength by heating it in the presence of sulfur, which results in three-dimensional cross-linking of the chain rubber molecules (polyisoprene) bonded to each other by sulfur atoms.
[8] An example of major air pollutant is –
A.
Oxygen
B.
Carbon monoxide
C.
Helium
D.
Carbon dioxide
Ans:
Carbon monoxide
Explanation :
Carbon monoxide (CO) is a colourless, odorless, non-irritating but very poisonous gas which is a product by incomplete combustion of fuel such as natural gas, coal or wood. Vehicular exhaust is a major source of carbon monoxide.
[9] The metal, used to galvanise iron to protect it from rusting is -
A.
Zine
B.
Chromium
C.
Lead
D.
Antimony
Ans:
Zine
Explanation :
Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. Although galvanization can be done with electrochemical and electro-deposition processes, the most common method in current use is hot-dip galvanization, in which steel parts are submerged in a bath of molten zinc.
[10] Which of the following gases is mixed with oxygen for breathing by divers in aqualungs?
A.
Methane
B.
Nitrogen
C.
Helium
D.
Hydrogen
Ans:
Nitrogen
Explanation :
For some diving, has mixtures other than normal atmospheric air (21 % oxygen, 78% nitrogen, 1% trace gases) can be used, so long as the diver is properly trained in their use. The most commonly used mixture is Nitrox, also referred to as Enriched Air Nitrox (EAN), which is air with extra oxygen, often with 32% or 36% oxygen, and thus less nitrogen, reducing the likelihood of decompression sickness or allowing longer exposure to the same pressure for equal risk.
[11] The material known in commerce as Terylene is a –
A.
Synthetic fibre
B.
Natural fibre
C.
Modified natural fibre
D.
Blend of cotton and silk
Ans:
Synthetic fibre
Explanation :
Terylene is the name for a synthetic polyester fibre. It is a synthetic polyester fibre or fabric based on terephthalic acid, characterized by lightness and crease resistance and used for clothing, sheets, ropes, sails, etc.
[12] Among the fuels given below, the one with highest calorific value is –
A.
Coke
B.
Coal
C.
Wood
D.
Natural gas
Ans:
Natural gas
Explanation :
The calorific values of different fuels (in Kcal/kg) in dry state are: Wood: 3500; Coal: 4000-7000; Coke: 6500; and Natural Gas: 8600 Kcal/kg.
[13] Electric bulbs are filled with –
A.
Nitrogen
B.
Carbon dioxide
C.
Argon
D.
Oxygen
Ans:
Argon
Explanation :
Argon is produced industrially by the fractional distillation of liquid air. Argon is mostly used as an inert shielding has in welding and other high-temperature industrial processes where ordinarily non-reactive substances become reactive; for example, an argon atmosphere is used in graphite electric furnaces to prevent the graphite from burning. Argon bas also has uses in incandescent and fluorescent lighting, and other types of gas discharge tubes. Argon makes a distinctive blue-green gas laser.
[14] The purest form of Iron is :
A.
Cast iron
B.
Steel
C.
Pig iron
D.
Wrought iron
Ans:
Wrought iron
Explanation :
Wrought iron is an iron alloy with a very low carbon content in Contrast to steel, and has fibrous inclusions, known as slag. This is what gives it a "grain" resembling wood, which is visible when it is etched or bent to the point of failure. Wrought iron is tough, malleable, ductile and easily welded. Historically, it was known as "commercially pure iron"; however, it no longer qualifies because current standards for commercially pure iron require a carbon content of less than 0.008 wt%.
[15] Which of the following metals are present in hemoglobin and chlorophyll, respectively?
A.
Fe and Mg
B.
Fe and Zn
C.
Mg and Zn
D.
Zn and Mg
Ans:
Fe and Mg
Explanation :
Fe and Mg metals are present in hemoglobin and Chlorophyll respectively.
[16] Atomic mass of Nitrogen is 14 and that of Hydrogen is 1. What will be the molecular mass of Ammonia?
A.
18
B.
17
C.
16
D.
15
Ans:
17
Explanation :
Ammonia (NH3) is composed of one atom of Nitrogen and three Hydrogen atoms. This means that its molar mass of ammonia will be the sum of the molar mass of one nitrogen atom and three times the molar mass of a hydrogen atom.
[17] Silver halides are used in photographic plates because they are -
A.
oxidised in air
B.
soluble in hyposolution
C.
reduced by light
D.
totally colourless
Ans:
reduced by light
Explanation :
The light-sensitive chemicals used in photographic film and paper are silver halides. Silver halides are used in photographic film and photographic paper, including graphic art film and paper, where silver halide crystals in gelatin are coated on to a film base, glass or paper substrate. When a silver halide crystal is exposed to light, a sensitivity speck on the surface of the crystal is turned into a small speck of metallic silver (these comprise the invisible or latent image). If the speck of silver contains approximately four or more atoms, it is rendered developable - meaning that it can undergo development which turns the entire crystal into metallic silver.
[18] Tetra ethyle lead (TEL) is -
A.
a catalyst in burning fossil fuel
B.
an antioxidant
C.
areductant
D.
an antiknock compound
Ans:
an antiknock compound
Explanation :
Tetraethyl lead was extensively used as an additive to gasoline, wherein it served as an effective antiknock agent and prevented exhaust valve and seat wear. The use of TEL in gasoline started in the US, while in Europe, alcohol was initially used. The advantages of leaded gasoline — its higher enemy content and storage quality —eventually led to a universal switch to leaded fuel. One of the greatest advantages of TEL over other antiknock agents or the use of high-octane blend stocks is the very low concentrations needed. Typical formulations called for 1 part of prepared TEL to 1260 parts untreated gasoline.
[19] Which metal is heaviest -
A.
osmium
B.
mercury
C.
iron
D.
nickel
Ans:
osmium
Explanation :
I assume by "heaviest," you mean "densest;" in that case, the densest chemical element is osmium (which is a metal). Osmium has a density of around 22 grams per cubic centimeter.
[20] The term PVC used in the plastic industry stands for -
A.
polyvinyl chloride
B.
polyvinyl carbonate
C.
phosphor vanadium chloride
D.
phosphavinyl chloride
Ans:
polyvinyl chloride
Explanation :
Polyvinyl chloride is the world's third-most widely produced synthetic plastic polymer, after polyethylene and polypropylene. About 40 million tones are produced per year.
[21] Rusting of iron takes place due to –
A.
oxidation
B.
carbonation
C.
exfoliation
D.
corrosion
Ans:
oxidation
Explanation :
The rusting of iron is an electrochemical process that begins with the transfer of electrons from iron to oxygen. The rate of corrosion is affected by water and accelerated by electrolytes, as illustrated by the effects of road salt on the corrosion of automobiles. When impure (cast) iron is in contact with water, oxygen, or other strong oxidants, or acids, it rusts.
[22] German silver used for making utensils is an alloy of –
A.
Copper, silver, nickel
B.
Copper, zinc, nickel
C.
copper, zinc, aluminium
D.
copper, nickel, aluminium
Ans:
Copper, zinc, nickel
Explanation :
Nickel silver, also known as German silver, Argentan, new silver, nickel brass, albata, alpacca, or electrum, is a copper alloy with nickel and often zinc. The usual formulation is 60% copper, 20% nickel and 20% zinc. Nickel silver is named for its silvery appearance, but it contains no elemental silver unless plated. The name "German silver" refers to its development by 19th-century German metalworkers in imitation of the Chinese alloy known as paktong.
[23] Sour milk contains –
A.
acetic acid
B.
tartaric acid
C.
citric acid
D.
lactic acid
Ans:
lactic acid
Explanation :
Lactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3. Lactic acid is found primarily in sour milk products, such as koumiss, laban, yogurt, kefir, and some cottage cheeses. The casein in fermented milk is coagulated (curdled) by lactic acid.
[24] The acid used in lead storage cells is –
A.
phosphoric acid
B.
hydrochloric acid
C.
nitric acid
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Lead-acid batteries, invented in 1859 by French physicist Gaston Plante, are the oldest type of rechargeable battery. Despite having a very low energy-to-weight ratio and a low energy-to-volume ratio, their ability to supply high surge currents means that the cells maintain a relatively large power- to-weight ratio. These features, along with their low cost, make them attractive for use in motor vehicles to provide the high current required by automobile starter motors.
[25] Milk is an example of -
A.
suspension
B.
true solution
C.
emulsion
D.
gel
Ans:
emulsion
Explanation :
An emulsion is a mixture of two or more liquids that are normally immiscible (nonmixable or unblendable). Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion should be used when both the dispersed and the continuous phase are liquids. In an emulsion, one liquid (the dispersed phase) is dispersed in the other (the continuous phase). Examples of emulsions include vinaigrettes, milk, mayonnaise, and some cutting fluids for metal working. The photo-sensitive side of photographic film is also an example of a colloid. The word “emulsion” comes from the Latin word for “to milk”, as milk is (among other things) an emulsion of milk fat and water.
Explanation :
Vulcanization of rubber is a process of improvement of the rubber elasticity and strength by heating it in the presence of sulfur, which results in three-dimensional cross-linking of the chain rubber molecules (polyisoprene) bonded to each other by sulfur atoms.
[8] An example of major air pollutant is –
A.
Oxygen
B.
Carbon monoxide
C.
Helium
D.
Carbon dioxide
Ans:
Carbon monoxide
Explanation :
Carbon monoxide (CO) is a colourless, odorless, non-irritating but very poisonous gas which is a product by incomplete combustion of fuel such as natural gas, coal or wood. Vehicular exhaust is a major source of carbon monoxide.
[9] The metal, used to galvanise iron to protect it from rusting is -
A.
Zine
B.
Chromium
C.
Lead
D.
Antimony
Ans:
Zine
Explanation :
Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. Although galvanization can be done with electrochemical and electro-deposition processes, the most common method in current use is hot-dip galvanization, in which steel parts are submerged in a bath of molten zinc.
[10] Which of the following gases is mixed with oxygen for breathing by divers in aqualungs?
A.
Methane
B.
Nitrogen
C.
Helium
D.
Hydrogen
Ans:
Nitrogen
Explanation :
For some diving, has mixtures other than normal atmospheric air (21 % oxygen, 78% nitrogen, 1% trace gases) can be used, so long as the diver is properly trained in their use. The most commonly used mixture is Nitrox, also referred to as Enriched Air Nitrox (EAN), which is air with extra oxygen, often with 32% or 36% oxygen, and thus less nitrogen, reducing the likelihood of decompression sickness or allowing longer exposure to the same pressure for equal risk.
[11] The material known in commerce as Terylene is a –
A.
Synthetic fibre
B.
Natural fibre
C.
Modified natural fibre
D.
Blend of cotton and silk
Ans:
Synthetic fibre
Explanation :
Terylene is the name for a synthetic polyester fibre. It is a synthetic polyester fibre or fabric based on terephthalic acid, characterized by lightness and crease resistance and used for clothing, sheets, ropes, sails, etc.
[12] Among the fuels given below, the one with highest calorific value is –
A.
Coke
B.
Coal
C.
Wood
D.
Natural gas
Ans:
Natural gas
Explanation :
The calorific values of different fuels (in Kcal/kg) in dry state are: Wood: 3500; Coal: 4000-7000; Coke: 6500; and Natural Gas: 8600 Kcal/kg.
[13] Electric bulbs are filled with –
A.
Nitrogen
B.
Carbon dioxide
C.
Argon
D.
Oxygen
Ans:
Argon
Explanation :
Argon is produced industrially by the fractional distillation of liquid air. Argon is mostly used as an inert shielding has in welding and other high-temperature industrial processes where ordinarily non-reactive substances become reactive; for example, an argon atmosphere is used in graphite electric furnaces to prevent the graphite from burning. Argon bas also has uses in incandescent and fluorescent lighting, and other types of gas discharge tubes. Argon makes a distinctive blue-green gas laser.
[14] The purest form of Iron is :
A.
Cast iron
B.
Steel
C.
Pig iron
D.
Wrought iron
Ans:
Wrought iron
Explanation :
Wrought iron is an iron alloy with a very low carbon content in Contrast to steel, and has fibrous inclusions, known as slag. This is what gives it a "grain" resembling wood, which is visible when it is etched or bent to the point of failure. Wrought iron is tough, malleable, ductile and easily welded. Historically, it was known as "commercially pure iron"; however, it no longer qualifies because current standards for commercially pure iron require a carbon content of less than 0.008 wt%.
[15] Which of the following metals are present in hemoglobin and chlorophyll, respectively?
A.
Fe and Mg
B.
Fe and Zn
C.
Mg and Zn
D.
Zn and Mg
Ans:
Fe and Mg
Explanation :
Fe and Mg metals are present in hemoglobin and Chlorophyll respectively.
[16] Atomic mass of Nitrogen is 14 and that of Hydrogen is 1. What will be the molecular mass of Ammonia?
A.
18
B.
17
C.
16
D.
15
Ans:
17
Explanation :
Ammonia (NH3) is composed of one atom of Nitrogen and three Hydrogen atoms. This means that its molar mass of ammonia will be the sum of the molar mass of one nitrogen atom and three times the molar mass of a hydrogen atom.
[17] Silver halides are used in photographic plates because they are -
A.
oxidised in air
B.
soluble in hyposolution
C.
reduced by light
D.
totally colourless
Ans:
reduced by light
Explanation :
The light-sensitive chemicals used in photographic film and paper are silver halides. Silver halides are used in photographic film and photographic paper, including graphic art film and paper, where silver halide crystals in gelatin are coated on to a film base, glass or paper substrate. When a silver halide crystal is exposed to light, a sensitivity speck on the surface of the crystal is turned into a small speck of metallic silver (these comprise the invisible or latent image). If the speck of silver contains approximately four or more atoms, it is rendered developable - meaning that it can undergo development which turns the entire crystal into metallic silver.
[18] Tetra ethyle lead (TEL) is -
A.
a catalyst in burning fossil fuel
B.
an antioxidant
C.
areductant
D.
an antiknock compound
Ans:
an antiknock compound
Explanation :
Tetraethyl lead was extensively used as an additive to gasoline, wherein it served as an effective antiknock agent and prevented exhaust valve and seat wear. The use of TEL in gasoline started in the US, while in Europe, alcohol was initially used. The advantages of leaded gasoline — its higher enemy content and storage quality —eventually led to a universal switch to leaded fuel. One of the greatest advantages of TEL over other antiknock agents or the use of high-octane blend stocks is the very low concentrations needed. Typical formulations called for 1 part of prepared TEL to 1260 parts untreated gasoline.
[19] Which metal is heaviest -
A.
osmium
B.
mercury
C.
iron
D.
nickel
Ans:
osmium
Explanation :
I assume by "heaviest," you mean "densest;" in that case, the densest chemical element is osmium (which is a metal). Osmium has a density of around 22 grams per cubic centimeter.
[20] The term PVC used in the plastic industry stands for -
A.
polyvinyl chloride
B.
polyvinyl carbonate
C.
phosphor vanadium chloride
D.
phosphavinyl chloride
Ans:
polyvinyl chloride
Explanation :
Polyvinyl chloride is the world's third-most widely produced synthetic plastic polymer, after polyethylene and polypropylene. About 40 million tones are produced per year.
[21] Rusting of iron takes place due to –
A.
oxidation
B.
carbonation
C.
exfoliation
D.
corrosion
Ans:
oxidation
Explanation :
The rusting of iron is an electrochemical process that begins with the transfer of electrons from iron to oxygen. The rate of corrosion is affected by water and accelerated by electrolytes, as illustrated by the effects of road salt on the corrosion of automobiles. When impure (cast) iron is in contact with water, oxygen, or other strong oxidants, or acids, it rusts.
[22] German silver used for making utensils is an alloy of –
A.
Copper, silver, nickel
B.
Copper, zinc, nickel
C.
copper, zinc, aluminium
D.
copper, nickel, aluminium
Ans:
Copper, zinc, nickel
Explanation :
Nickel silver, also known as German silver, Argentan, new silver, nickel brass, albata, alpacca, or electrum, is a copper alloy with nickel and often zinc. The usual formulation is 60% copper, 20% nickel and 20% zinc. Nickel silver is named for its silvery appearance, but it contains no elemental silver unless plated. The name "German silver" refers to its development by 19th-century German metalworkers in imitation of the Chinese alloy known as paktong.
[23] Sour milk contains –
A.
acetic acid
B.
tartaric acid
C.
citric acid
D.
lactic acid
Ans:
lactic acid
Explanation :
Lactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3. Lactic acid is found primarily in sour milk products, such as koumiss, laban, yogurt, kefir, and some cottage cheeses. The casein in fermented milk is coagulated (curdled) by lactic acid.
[24] The acid used in lead storage cells is –
A.
phosphoric acid
B.
hydrochloric acid
C.
nitric acid
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Lead-acid batteries, invented in 1859 by French physicist Gaston Plante, are the oldest type of rechargeable battery. Despite having a very low energy-to-weight ratio and a low energy-to-volume ratio, their ability to supply high surge currents means that the cells maintain a relatively large power- to-weight ratio. These features, along with their low cost, make them attractive for use in motor vehicles to provide the high current required by automobile starter motors.
[25] Milk is an example of -
A.
suspension
B.
true solution
C.
emulsion
D.
gel
Ans:
emulsion
Explanation :
An emulsion is a mixture of two or more liquids that are normally immiscible (nonmixable or unblendable). Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion should be used when both the dispersed and the continuous phase are liquids. In an emulsion, one liquid (the dispersed phase) is dispersed in the other (the continuous phase). Examples of emulsions include vinaigrettes, milk, mayonnaise, and some cutting fluids for metal working. The photo-sensitive side of photographic film is also an example of a colloid. The word “emulsion” comes from the Latin word for “to milk”, as milk is (among other things) an emulsion of milk fat and water.
Explanation :
Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. Although galvanization can be done with electrochemical and electro-deposition processes, the most common method in current use is hot-dip galvanization, in which steel parts are submerged in a bath of molten zinc.
[10] Which of the following gases is mixed with oxygen for breathing by divers in aqualungs?
A.
Methane
B.
Nitrogen
C.
Helium
D.
Hydrogen
Ans:
Nitrogen
Explanation :
For some diving, has mixtures other than normal atmospheric air (21 % oxygen, 78% nitrogen, 1% trace gases) can be used, so long as the diver is properly trained in their use. The most commonly used mixture is Nitrox, also referred to as Enriched Air Nitrox (EAN), which is air with extra oxygen, often with 32% or 36% oxygen, and thus less nitrogen, reducing the likelihood of decompression sickness or allowing longer exposure to the same pressure for equal risk.
[11] The material known in commerce as Terylene is a –
A.
Synthetic fibre
B.
Natural fibre
C.
Modified natural fibre
D.
Blend of cotton and silk
Ans:
Synthetic fibre
Explanation :
Terylene is the name for a synthetic polyester fibre. It is a synthetic polyester fibre or fabric based on terephthalic acid, characterized by lightness and crease resistance and used for clothing, sheets, ropes, sails, etc.
[12] Among the fuels given below, the one with highest calorific value is –
A.
Coke
B.
Coal
C.
Wood
D.
Natural gas
Ans:
Natural gas
Explanation :
The calorific values of different fuels (in Kcal/kg) in dry state are: Wood: 3500; Coal: 4000-7000; Coke: 6500; and Natural Gas: 8600 Kcal/kg.
[13] Electric bulbs are filled with –
A.
Nitrogen
B.
Carbon dioxide
C.
Argon
D.
Oxygen
Ans:
Argon
Explanation :
Argon is produced industrially by the fractional distillation of liquid air. Argon is mostly used as an inert shielding has in welding and other high-temperature industrial processes where ordinarily non-reactive substances become reactive; for example, an argon atmosphere is used in graphite electric furnaces to prevent the graphite from burning. Argon bas also has uses in incandescent and fluorescent lighting, and other types of gas discharge tubes. Argon makes a distinctive blue-green gas laser.
[14] The purest form of Iron is :
A.
Cast iron
B.
Steel
C.
Pig iron
D.
Wrought iron
Ans:
Wrought iron
Explanation :
Wrought iron is an iron alloy with a very low carbon content in Contrast to steel, and has fibrous inclusions, known as slag. This is what gives it a "grain" resembling wood, which is visible when it is etched or bent to the point of failure. Wrought iron is tough, malleable, ductile and easily welded. Historically, it was known as "commercially pure iron"; however, it no longer qualifies because current standards for commercially pure iron require a carbon content of less than 0.008 wt%.
[15] Which of the following metals are present in hemoglobin and chlorophyll, respectively?
A.
Fe and Mg
B.
Fe and Zn
C.
Mg and Zn
D.
Zn and Mg
Ans:
Fe and Mg
Explanation :
Fe and Mg metals are present in hemoglobin and Chlorophyll respectively.
[16] Atomic mass of Nitrogen is 14 and that of Hydrogen is 1. What will be the molecular mass of Ammonia?
A.
18
B.
17
C.
16
D.
15
Ans:
17
Explanation :
Ammonia (NH3) is composed of one atom of Nitrogen and three Hydrogen atoms. This means that its molar mass of ammonia will be the sum of the molar mass of one nitrogen atom and three times the molar mass of a hydrogen atom.
[17] Silver halides are used in photographic plates because they are -
A.
oxidised in air
B.
soluble in hyposolution
C.
reduced by light
D.
totally colourless
Ans:
reduced by light
Explanation :
The light-sensitive chemicals used in photographic film and paper are silver halides. Silver halides are used in photographic film and photographic paper, including graphic art film and paper, where silver halide crystals in gelatin are coated on to a film base, glass or paper substrate. When a silver halide crystal is exposed to light, a sensitivity speck on the surface of the crystal is turned into a small speck of metallic silver (these comprise the invisible or latent image). If the speck of silver contains approximately four or more atoms, it is rendered developable - meaning that it can undergo development which turns the entire crystal into metallic silver.
[18] Tetra ethyle lead (TEL) is -
A.
a catalyst in burning fossil fuel
B.
an antioxidant
C.
areductant
D.
an antiknock compound
Ans:
an antiknock compound
Explanation :
Tetraethyl lead was extensively used as an additive to gasoline, wherein it served as an effective antiknock agent and prevented exhaust valve and seat wear. The use of TEL in gasoline started in the US, while in Europe, alcohol was initially used. The advantages of leaded gasoline — its higher enemy content and storage quality —eventually led to a universal switch to leaded fuel. One of the greatest advantages of TEL over other antiknock agents or the use of high-octane blend stocks is the very low concentrations needed. Typical formulations called for 1 part of prepared TEL to 1260 parts untreated gasoline.
[19] Which metal is heaviest -
A.
osmium
B.
mercury
C.
iron
D.
nickel
Ans:
osmium
Explanation :
I assume by "heaviest," you mean "densest;" in that case, the densest chemical element is osmium (which is a metal). Osmium has a density of around 22 grams per cubic centimeter.
[20] The term PVC used in the plastic industry stands for -
A.
polyvinyl chloride
B.
polyvinyl carbonate
C.
phosphor vanadium chloride
D.
phosphavinyl chloride
Ans:
polyvinyl chloride
Explanation :
Polyvinyl chloride is the world's third-most widely produced synthetic plastic polymer, after polyethylene and polypropylene. About 40 million tones are produced per year.
[21] Rusting of iron takes place due to –
A.
oxidation
B.
carbonation
C.
exfoliation
D.
corrosion
Ans:
oxidation
Explanation :
The rusting of iron is an electrochemical process that begins with the transfer of electrons from iron to oxygen. The rate of corrosion is affected by water and accelerated by electrolytes, as illustrated by the effects of road salt on the corrosion of automobiles. When impure (cast) iron is in contact with water, oxygen, or other strong oxidants, or acids, it rusts.
[22] German silver used for making utensils is an alloy of –
A.
Copper, silver, nickel
B.
Copper, zinc, nickel
C.
copper, zinc, aluminium
D.
copper, nickel, aluminium
Ans:
Copper, zinc, nickel
Explanation :
Nickel silver, also known as German silver, Argentan, new silver, nickel brass, albata, alpacca, or electrum, is a copper alloy with nickel and often zinc. The usual formulation is 60% copper, 20% nickel and 20% zinc. Nickel silver is named for its silvery appearance, but it contains no elemental silver unless plated. The name "German silver" refers to its development by 19th-century German metalworkers in imitation of the Chinese alloy known as paktong.
[23] Sour milk contains –
A.
acetic acid
B.
tartaric acid
C.
citric acid
D.
lactic acid
Ans:
lactic acid
Explanation :
Lactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3. Lactic acid is found primarily in sour milk products, such as koumiss, laban, yogurt, kefir, and some cottage cheeses. The casein in fermented milk is coagulated (curdled) by lactic acid.
[24] The acid used in lead storage cells is –
A.
phosphoric acid
B.
hydrochloric acid
C.
nitric acid
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Lead-acid batteries, invented in 1859 by French physicist Gaston Plante, are the oldest type of rechargeable battery. Despite having a very low energy-to-weight ratio and a low energy-to-volume ratio, their ability to supply high surge currents means that the cells maintain a relatively large power- to-weight ratio. These features, along with their low cost, make them attractive for use in motor vehicles to provide the high current required by automobile starter motors.
[25] Milk is an example of -
A.
suspension
B.
true solution
C.
emulsion
D.
gel
Ans:
emulsion
Explanation :
An emulsion is a mixture of two or more liquids that are normally immiscible (nonmixable or unblendable). Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion should be used when both the dispersed and the continuous phase are liquids. In an emulsion, one liquid (the dispersed phase) is dispersed in the other (the continuous phase). Examples of emulsions include vinaigrettes, milk, mayonnaise, and some cutting fluids for metal working. The photo-sensitive side of photographic film is also an example of a colloid. The word “emulsion” comes from the Latin word for “to milk”, as milk is (among other things) an emulsion of milk fat and water.
Explanation :
Terylene is the name for a synthetic polyester fibre. It is a synthetic polyester fibre or fabric based on terephthalic acid, characterized by lightness and crease resistance and used for clothing, sheets, ropes, sails, etc.
[12] Among the fuels given below, the one with highest calorific value is –
A.
Coke
B.
Coal
C.
Wood
D.
Natural gas
Ans:
Natural gas
Explanation :
The calorific values of different fuels (in Kcal/kg) in dry state are: Wood: 3500; Coal: 4000-7000; Coke: 6500; and Natural Gas: 8600 Kcal/kg.
[13] Electric bulbs are filled with –
A.
Nitrogen
B.
Carbon dioxide
C.
Argon
D.
Oxygen
Ans:
Argon
Explanation :
Argon is produced industrially by the fractional distillation of liquid air. Argon is mostly used as an inert shielding has in welding and other high-temperature industrial processes where ordinarily non-reactive substances become reactive; for example, an argon atmosphere is used in graphite electric furnaces to prevent the graphite from burning. Argon bas also has uses in incandescent and fluorescent lighting, and other types of gas discharge tubes. Argon makes a distinctive blue-green gas laser.
[14] The purest form of Iron is :
A.
Cast iron
B.
Steel
C.
Pig iron
D.
Wrought iron
Ans:
Wrought iron
Explanation :
Wrought iron is an iron alloy with a very low carbon content in Contrast to steel, and has fibrous inclusions, known as slag. This is what gives it a "grain" resembling wood, which is visible when it is etched or bent to the point of failure. Wrought iron is tough, malleable, ductile and easily welded. Historically, it was known as "commercially pure iron"; however, it no longer qualifies because current standards for commercially pure iron require a carbon content of less than 0.008 wt%.
[15] Which of the following metals are present in hemoglobin and chlorophyll, respectively?
A.
Fe and Mg
B.
Fe and Zn
C.
Mg and Zn
D.
Zn and Mg
Ans:
Fe and Mg
Explanation :
Fe and Mg metals are present in hemoglobin and Chlorophyll respectively.
[16] Atomic mass of Nitrogen is 14 and that of Hydrogen is 1. What will be the molecular mass of Ammonia?
A.
18
B.
17
C.
16
D.
15
Ans:
17
Explanation :
Ammonia (NH3) is composed of one atom of Nitrogen and three Hydrogen atoms. This means that its molar mass of ammonia will be the sum of the molar mass of one nitrogen atom and three times the molar mass of a hydrogen atom.
[17] Silver halides are used in photographic plates because they are -
A.
oxidised in air
B.
soluble in hyposolution
C.
reduced by light
D.
totally colourless
Ans:
reduced by light
Explanation :
The light-sensitive chemicals used in photographic film and paper are silver halides. Silver halides are used in photographic film and photographic paper, including graphic art film and paper, where silver halide crystals in gelatin are coated on to a film base, glass or paper substrate. When a silver halide crystal is exposed to light, a sensitivity speck on the surface of the crystal is turned into a small speck of metallic silver (these comprise the invisible or latent image). If the speck of silver contains approximately four or more atoms, it is rendered developable - meaning that it can undergo development which turns the entire crystal into metallic silver.
[18] Tetra ethyle lead (TEL) is -
A.
a catalyst in burning fossil fuel
B.
an antioxidant
C.
areductant
D.
an antiknock compound
Ans:
an antiknock compound
Explanation :
Tetraethyl lead was extensively used as an additive to gasoline, wherein it served as an effective antiknock agent and prevented exhaust valve and seat wear. The use of TEL in gasoline started in the US, while in Europe, alcohol was initially used. The advantages of leaded gasoline — its higher enemy content and storage quality —eventually led to a universal switch to leaded fuel. One of the greatest advantages of TEL over other antiknock agents or the use of high-octane blend stocks is the very low concentrations needed. Typical formulations called for 1 part of prepared TEL to 1260 parts untreated gasoline.
[19] Which metal is heaviest -
A.
osmium
B.
mercury
C.
iron
D.
nickel
Ans:
osmium
Explanation :
I assume by "heaviest," you mean "densest;" in that case, the densest chemical element is osmium (which is a metal). Osmium has a density of around 22 grams per cubic centimeter.
[20] The term PVC used in the plastic industry stands for -
A.
polyvinyl chloride
B.
polyvinyl carbonate
C.
phosphor vanadium chloride
D.
phosphavinyl chloride
Ans:
polyvinyl chloride
Explanation :
Polyvinyl chloride is the world's third-most widely produced synthetic plastic polymer, after polyethylene and polypropylene. About 40 million tones are produced per year.
[21] Rusting of iron takes place due to –
A.
oxidation
B.
carbonation
C.
exfoliation
D.
corrosion
Ans:
oxidation
Explanation :
The rusting of iron is an electrochemical process that begins with the transfer of electrons from iron to oxygen. The rate of corrosion is affected by water and accelerated by electrolytes, as illustrated by the effects of road salt on the corrosion of automobiles. When impure (cast) iron is in contact with water, oxygen, or other strong oxidants, or acids, it rusts.
[22] German silver used for making utensils is an alloy of –
A.
Copper, silver, nickel
B.
Copper, zinc, nickel
C.
copper, zinc, aluminium
D.
copper, nickel, aluminium
Ans:
Copper, zinc, nickel
Explanation :
Nickel silver, also known as German silver, Argentan, new silver, nickel brass, albata, alpacca, or electrum, is a copper alloy with nickel and often zinc. The usual formulation is 60% copper, 20% nickel and 20% zinc. Nickel silver is named for its silvery appearance, but it contains no elemental silver unless plated. The name "German silver" refers to its development by 19th-century German metalworkers in imitation of the Chinese alloy known as paktong.
[23] Sour milk contains –
A.
acetic acid
B.
tartaric acid
C.
citric acid
D.
lactic acid
Ans:
lactic acid
Explanation :
Lactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3. Lactic acid is found primarily in sour milk products, such as koumiss, laban, yogurt, kefir, and some cottage cheeses. The casein in fermented milk is coagulated (curdled) by lactic acid.
[24] The acid used in lead storage cells is –
A.
phosphoric acid
B.
hydrochloric acid
C.
nitric acid
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Lead-acid batteries, invented in 1859 by French physicist Gaston Plante, are the oldest type of rechargeable battery. Despite having a very low energy-to-weight ratio and a low energy-to-volume ratio, their ability to supply high surge currents means that the cells maintain a relatively large power- to-weight ratio. These features, along with their low cost, make them attractive for use in motor vehicles to provide the high current required by automobile starter motors.
[25] Milk is an example of -
A.
suspension
B.
true solution
C.
emulsion
D.
gel
Ans:
emulsion
Explanation :
An emulsion is a mixture of two or more liquids that are normally immiscible (nonmixable or unblendable). Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion should be used when both the dispersed and the continuous phase are liquids. In an emulsion, one liquid (the dispersed phase) is dispersed in the other (the continuous phase). Examples of emulsions include vinaigrettes, milk, mayonnaise, and some cutting fluids for metal working. The photo-sensitive side of photographic film is also an example of a colloid. The word “emulsion” comes from the Latin word for “to milk”, as milk is (among other things) an emulsion of milk fat and water.
Explanation :
Argon is produced industrially by the fractional distillation of liquid air. Argon is mostly used as an inert shielding has in welding and other high-temperature industrial processes where ordinarily non-reactive substances become reactive; for example, an argon atmosphere is used in graphite electric furnaces to prevent the graphite from burning. Argon bas also has uses in incandescent and fluorescent lighting, and other types of gas discharge tubes. Argon makes a distinctive blue-green gas laser.
[14] The purest form of Iron is :
A.
Cast iron
B.
Steel
C.
Pig iron
D.
Wrought iron
Ans:
Wrought iron
Explanation :
Wrought iron is an iron alloy with a very low carbon content in Contrast to steel, and has fibrous inclusions, known as slag. This is what gives it a "grain" resembling wood, which is visible when it is etched or bent to the point of failure. Wrought iron is tough, malleable, ductile and easily welded. Historically, it was known as "commercially pure iron"; however, it no longer qualifies because current standards for commercially pure iron require a carbon content of less than 0.008 wt%.
[15] Which of the following metals are present in hemoglobin and chlorophyll, respectively?
A.
Fe and Mg
B.
Fe and Zn
C.
Mg and Zn
D.
Zn and Mg
Ans:
Fe and Mg
Explanation :
Fe and Mg metals are present in hemoglobin and Chlorophyll respectively.
[16] Atomic mass of Nitrogen is 14 and that of Hydrogen is 1. What will be the molecular mass of Ammonia?
A.
18
B.
17
C.
16
D.
15
Ans:
17
Explanation :
Ammonia (NH3) is composed of one atom of Nitrogen and three Hydrogen atoms. This means that its molar mass of ammonia will be the sum of the molar mass of one nitrogen atom and three times the molar mass of a hydrogen atom.
[17] Silver halides are used in photographic plates because they are -
A.
oxidised in air
B.
soluble in hyposolution
C.
reduced by light
D.
totally colourless
Ans:
reduced by light
Explanation :
The light-sensitive chemicals used in photographic film and paper are silver halides. Silver halides are used in photographic film and photographic paper, including graphic art film and paper, where silver halide crystals in gelatin are coated on to a film base, glass or paper substrate. When a silver halide crystal is exposed to light, a sensitivity speck on the surface of the crystal is turned into a small speck of metallic silver (these comprise the invisible or latent image). If the speck of silver contains approximately four or more atoms, it is rendered developable - meaning that it can undergo development which turns the entire crystal into metallic silver.
[18] Tetra ethyle lead (TEL) is -
A.
a catalyst in burning fossil fuel
B.
an antioxidant
C.
areductant
D.
an antiknock compound
Ans:
an antiknock compound
Explanation :
Tetraethyl lead was extensively used as an additive to gasoline, wherein it served as an effective antiknock agent and prevented exhaust valve and seat wear. The use of TEL in gasoline started in the US, while in Europe, alcohol was initially used. The advantages of leaded gasoline — its higher enemy content and storage quality —eventually led to a universal switch to leaded fuel. One of the greatest advantages of TEL over other antiknock agents or the use of high-octane blend stocks is the very low concentrations needed. Typical formulations called for 1 part of prepared TEL to 1260 parts untreated gasoline.
[19] Which metal is heaviest -
A.
osmium
B.
mercury
C.
iron
D.
nickel
Ans:
osmium
Explanation :
I assume by "heaviest," you mean "densest;" in that case, the densest chemical element is osmium (which is a metal). Osmium has a density of around 22 grams per cubic centimeter.
[20] The term PVC used in the plastic industry stands for -
A.
polyvinyl chloride
B.
polyvinyl carbonate
C.
phosphor vanadium chloride
D.
phosphavinyl chloride
Ans:
polyvinyl chloride
Explanation :
Polyvinyl chloride is the world's third-most widely produced synthetic plastic polymer, after polyethylene and polypropylene. About 40 million tones are produced per year.
[21] Rusting of iron takes place due to –
A.
oxidation
B.
carbonation
C.
exfoliation
D.
corrosion
Ans:
oxidation
Explanation :
The rusting of iron is an electrochemical process that begins with the transfer of electrons from iron to oxygen. The rate of corrosion is affected by water and accelerated by electrolytes, as illustrated by the effects of road salt on the corrosion of automobiles. When impure (cast) iron is in contact with water, oxygen, or other strong oxidants, or acids, it rusts.
[22] German silver used for making utensils is an alloy of –
A.
Copper, silver, nickel
B.
Copper, zinc, nickel
C.
copper, zinc, aluminium
D.
copper, nickel, aluminium
Ans:
Copper, zinc, nickel
Explanation :
Nickel silver, also known as German silver, Argentan, new silver, nickel brass, albata, alpacca, or electrum, is a copper alloy with nickel and often zinc. The usual formulation is 60% copper, 20% nickel and 20% zinc. Nickel silver is named for its silvery appearance, but it contains no elemental silver unless plated. The name "German silver" refers to its development by 19th-century German metalworkers in imitation of the Chinese alloy known as paktong.
[23] Sour milk contains –
A.
acetic acid
B.
tartaric acid
C.
citric acid
D.
lactic acid
Ans:
lactic acid
Explanation :
Lactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3. Lactic acid is found primarily in sour milk products, such as koumiss, laban, yogurt, kefir, and some cottage cheeses. The casein in fermented milk is coagulated (curdled) by lactic acid.
[24] The acid used in lead storage cells is –
A.
phosphoric acid
B.
hydrochloric acid
C.
nitric acid
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Lead-acid batteries, invented in 1859 by French physicist Gaston Plante, are the oldest type of rechargeable battery. Despite having a very low energy-to-weight ratio and a low energy-to-volume ratio, their ability to supply high surge currents means that the cells maintain a relatively large power- to-weight ratio. These features, along with their low cost, make them attractive for use in motor vehicles to provide the high current required by automobile starter motors.
[25] Milk is an example of -
A.
suspension
B.
true solution
C.
emulsion
D.
gel
Ans:
emulsion
Explanation :
An emulsion is a mixture of two or more liquids that are normally immiscible (nonmixable or unblendable). Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion should be used when both the dispersed and the continuous phase are liquids. In an emulsion, one liquid (the dispersed phase) is dispersed in the other (the continuous phase). Examples of emulsions include vinaigrettes, milk, mayonnaise, and some cutting fluids for metal working. The photo-sensitive side of photographic film is also an example of a colloid. The word “emulsion” comes from the Latin word for “to milk”, as milk is (among other things) an emulsion of milk fat and water.
Explanation :
Fe and Mg metals are present in hemoglobin and Chlorophyll respectively.
[16] Atomic mass of Nitrogen is 14 and that of Hydrogen is 1. What will be the molecular mass of Ammonia?
A.
18
B.
17
C.
16
D.
15
Ans:
17
Explanation :
Ammonia (NH3) is composed of one atom of Nitrogen and three Hydrogen atoms. This means that its molar mass of ammonia will be the sum of the molar mass of one nitrogen atom and three times the molar mass of a hydrogen atom.
[17] Silver halides are used in photographic plates because they are -
A.
oxidised in air
B.
soluble in hyposolution
C.
reduced by light
D.
totally colourless
Ans:
reduced by light
Explanation :
The light-sensitive chemicals used in photographic film and paper are silver halides. Silver halides are used in photographic film and photographic paper, including graphic art film and paper, where silver halide crystals in gelatin are coated on to a film base, glass or paper substrate. When a silver halide crystal is exposed to light, a sensitivity speck on the surface of the crystal is turned into a small speck of metallic silver (these comprise the invisible or latent image). If the speck of silver contains approximately four or more atoms, it is rendered developable - meaning that it can undergo development which turns the entire crystal into metallic silver.
[18] Tetra ethyle lead (TEL) is -
A.
a catalyst in burning fossil fuel
B.
an antioxidant
C.
areductant
D.
an antiknock compound
Ans:
an antiknock compound
Explanation :
Tetraethyl lead was extensively used as an additive to gasoline, wherein it served as an effective antiknock agent and prevented exhaust valve and seat wear. The use of TEL in gasoline started in the US, while in Europe, alcohol was initially used. The advantages of leaded gasoline — its higher enemy content and storage quality —eventually led to a universal switch to leaded fuel. One of the greatest advantages of TEL over other antiknock agents or the use of high-octane blend stocks is the very low concentrations needed. Typical formulations called for 1 part of prepared TEL to 1260 parts untreated gasoline.
[19] Which metal is heaviest -
A.
osmium
B.
mercury
C.
iron
D.
nickel
Ans:
osmium
Explanation :
I assume by "heaviest," you mean "densest;" in that case, the densest chemical element is osmium (which is a metal). Osmium has a density of around 22 grams per cubic centimeter.
[20] The term PVC used in the plastic industry stands for -
A.
polyvinyl chloride
B.
polyvinyl carbonate
C.
phosphor vanadium chloride
D.
phosphavinyl chloride
Ans:
polyvinyl chloride
Explanation :
Polyvinyl chloride is the world's third-most widely produced synthetic plastic polymer, after polyethylene and polypropylene. About 40 million tones are produced per year.
[21] Rusting of iron takes place due to –
A.
oxidation
B.
carbonation
C.
exfoliation
D.
corrosion
Ans:
oxidation
Explanation :
The rusting of iron is an electrochemical process that begins with the transfer of electrons from iron to oxygen. The rate of corrosion is affected by water and accelerated by electrolytes, as illustrated by the effects of road salt on the corrosion of automobiles. When impure (cast) iron is in contact with water, oxygen, or other strong oxidants, or acids, it rusts.
[22] German silver used for making utensils is an alloy of –
A.
Copper, silver, nickel
B.
Copper, zinc, nickel
C.
copper, zinc, aluminium
D.
copper, nickel, aluminium
Ans:
Copper, zinc, nickel
Explanation :
Nickel silver, also known as German silver, Argentan, new silver, nickel brass, albata, alpacca, or electrum, is a copper alloy with nickel and often zinc. The usual formulation is 60% copper, 20% nickel and 20% zinc. Nickel silver is named for its silvery appearance, but it contains no elemental silver unless plated. The name "German silver" refers to its development by 19th-century German metalworkers in imitation of the Chinese alloy known as paktong.
[23] Sour milk contains –
A.
acetic acid
B.
tartaric acid
C.
citric acid
D.
lactic acid
Ans:
lactic acid
Explanation :
Lactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3. Lactic acid is found primarily in sour milk products, such as koumiss, laban, yogurt, kefir, and some cottage cheeses. The casein in fermented milk is coagulated (curdled) by lactic acid.
[24] The acid used in lead storage cells is –
A.
phosphoric acid
B.
hydrochloric acid
C.
nitric acid
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Lead-acid batteries, invented in 1859 by French physicist Gaston Plante, are the oldest type of rechargeable battery. Despite having a very low energy-to-weight ratio and a low energy-to-volume ratio, their ability to supply high surge currents means that the cells maintain a relatively large power- to-weight ratio. These features, along with their low cost, make them attractive for use in motor vehicles to provide the high current required by automobile starter motors.
[25] Milk is an example of -
A.
suspension
B.
true solution
C.
emulsion
D.
gel
Ans:
emulsion
Explanation :
An emulsion is a mixture of two or more liquids that are normally immiscible (nonmixable or unblendable). Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion should be used when both the dispersed and the continuous phase are liquids. In an emulsion, one liquid (the dispersed phase) is dispersed in the other (the continuous phase). Examples of emulsions include vinaigrettes, milk, mayonnaise, and some cutting fluids for metal working. The photo-sensitive side of photographic film is also an example of a colloid. The word “emulsion” comes from the Latin word for “to milk”, as milk is (among other things) an emulsion of milk fat and water.
Explanation :
The light-sensitive chemicals used in photographic film and paper are silver halides. Silver halides are used in photographic film and photographic paper, including graphic art film and paper, where silver halide crystals in gelatin are coated on to a film base, glass or paper substrate. When a silver halide crystal is exposed to light, a sensitivity speck on the surface of the crystal is turned into a small speck of metallic silver (these comprise the invisible or latent image). If the speck of silver contains approximately four or more atoms, it is rendered developable - meaning that it can undergo development which turns the entire crystal into metallic silver.
[18] Tetra ethyle lead (TEL) is -
A.
a catalyst in burning fossil fuel
B.
an antioxidant
C.
areductant
D.
an antiknock compound
Ans:
an antiknock compound
Explanation :
Tetraethyl lead was extensively used as an additive to gasoline, wherein it served as an effective antiknock agent and prevented exhaust valve and seat wear. The use of TEL in gasoline started in the US, while in Europe, alcohol was initially used. The advantages of leaded gasoline — its higher enemy content and storage quality —eventually led to a universal switch to leaded fuel. One of the greatest advantages of TEL over other antiknock agents or the use of high-octane blend stocks is the very low concentrations needed. Typical formulations called for 1 part of prepared TEL to 1260 parts untreated gasoline.
[19] Which metal is heaviest -
A.
osmium
B.
mercury
C.
iron
D.
nickel
Ans:
osmium
Explanation :
I assume by "heaviest," you mean "densest;" in that case, the densest chemical element is osmium (which is a metal). Osmium has a density of around 22 grams per cubic centimeter.
[20] The term PVC used in the plastic industry stands for -
A.
polyvinyl chloride
B.
polyvinyl carbonate
C.
phosphor vanadium chloride
D.
phosphavinyl chloride
Ans:
polyvinyl chloride
Explanation :
Polyvinyl chloride is the world's third-most widely produced synthetic plastic polymer, after polyethylene and polypropylene. About 40 million tones are produced per year.
[21] Rusting of iron takes place due to –
A.
oxidation
B.
carbonation
C.
exfoliation
D.
corrosion
Ans:
oxidation
Explanation :
The rusting of iron is an electrochemical process that begins with the transfer of electrons from iron to oxygen. The rate of corrosion is affected by water and accelerated by electrolytes, as illustrated by the effects of road salt on the corrosion of automobiles. When impure (cast) iron is in contact with water, oxygen, or other strong oxidants, or acids, it rusts.
[22] German silver used for making utensils is an alloy of –
A.
Copper, silver, nickel
B.
Copper, zinc, nickel
C.
copper, zinc, aluminium
D.
copper, nickel, aluminium
Ans:
Copper, zinc, nickel
Explanation :
Nickel silver, also known as German silver, Argentan, new silver, nickel brass, albata, alpacca, or electrum, is a copper alloy with nickel and often zinc. The usual formulation is 60% copper, 20% nickel and 20% zinc. Nickel silver is named for its silvery appearance, but it contains no elemental silver unless plated. The name "German silver" refers to its development by 19th-century German metalworkers in imitation of the Chinese alloy known as paktong.
[23] Sour milk contains –
A.
acetic acid
B.
tartaric acid
C.
citric acid
D.
lactic acid
Ans:
lactic acid
Explanation :
Lactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3. Lactic acid is found primarily in sour milk products, such as koumiss, laban, yogurt, kefir, and some cottage cheeses. The casein in fermented milk is coagulated (curdled) by lactic acid.
[24] The acid used in lead storage cells is –
A.
phosphoric acid
B.
hydrochloric acid
C.
nitric acid
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Lead-acid batteries, invented in 1859 by French physicist Gaston Plante, are the oldest type of rechargeable battery. Despite having a very low energy-to-weight ratio and a low energy-to-volume ratio, their ability to supply high surge currents means that the cells maintain a relatively large power- to-weight ratio. These features, along with their low cost, make them attractive for use in motor vehicles to provide the high current required by automobile starter motors.
[25] Milk is an example of -
A.
suspension
B.
true solution
C.
emulsion
D.
gel
Ans:
emulsion
Explanation :
An emulsion is a mixture of two or more liquids that are normally immiscible (nonmixable or unblendable). Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion should be used when both the dispersed and the continuous phase are liquids. In an emulsion, one liquid (the dispersed phase) is dispersed in the other (the continuous phase). Examples of emulsions include vinaigrettes, milk, mayonnaise, and some cutting fluids for metal working. The photo-sensitive side of photographic film is also an example of a colloid. The word “emulsion” comes from the Latin word for “to milk”, as milk is (among other things) an emulsion of milk fat and water.
Explanation :
I assume by "heaviest," you mean "densest;" in that case, the densest chemical element is osmium (which is a metal). Osmium has a density of around 22 grams per cubic centimeter.
[20] The term PVC used in the plastic industry stands for -
A.
polyvinyl chloride
B.
polyvinyl carbonate
C.
phosphor vanadium chloride
D.
phosphavinyl chloride
Ans:
polyvinyl chloride
Explanation :
Polyvinyl chloride is the world's third-most widely produced synthetic plastic polymer, after polyethylene and polypropylene. About 40 million tones are produced per year.
[21] Rusting of iron takes place due to –
A.
oxidation
B.
carbonation
C.
exfoliation
D.
corrosion
Ans:
oxidation
Explanation :
The rusting of iron is an electrochemical process that begins with the transfer of electrons from iron to oxygen. The rate of corrosion is affected by water and accelerated by electrolytes, as illustrated by the effects of road salt on the corrosion of automobiles. When impure (cast) iron is in contact with water, oxygen, or other strong oxidants, or acids, it rusts.
[22] German silver used for making utensils is an alloy of –
A.
Copper, silver, nickel
B.
Copper, zinc, nickel
C.
copper, zinc, aluminium
D.
copper, nickel, aluminium
Ans:
Copper, zinc, nickel
Explanation :
Nickel silver, also known as German silver, Argentan, new silver, nickel brass, albata, alpacca, or electrum, is a copper alloy with nickel and often zinc. The usual formulation is 60% copper, 20% nickel and 20% zinc. Nickel silver is named for its silvery appearance, but it contains no elemental silver unless plated. The name "German silver" refers to its development by 19th-century German metalworkers in imitation of the Chinese alloy known as paktong.
[23] Sour milk contains –
A.
acetic acid
B.
tartaric acid
C.
citric acid
D.
lactic acid
Ans:
lactic acid
Explanation :
Lactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3. Lactic acid is found primarily in sour milk products, such as koumiss, laban, yogurt, kefir, and some cottage cheeses. The casein in fermented milk is coagulated (curdled) by lactic acid.
[24] The acid used in lead storage cells is –
A.
phosphoric acid
B.
hydrochloric acid
C.
nitric acid
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Lead-acid batteries, invented in 1859 by French physicist Gaston Plante, are the oldest type of rechargeable battery. Despite having a very low energy-to-weight ratio and a low energy-to-volume ratio, their ability to supply high surge currents means that the cells maintain a relatively large power- to-weight ratio. These features, along with their low cost, make them attractive for use in motor vehicles to provide the high current required by automobile starter motors.
[25] Milk is an example of -
A.
suspension
B.
true solution
C.
emulsion
D.
gel
Ans:
emulsion
Explanation :
An emulsion is a mixture of two or more liquids that are normally immiscible (nonmixable or unblendable). Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion should be used when both the dispersed and the continuous phase are liquids. In an emulsion, one liquid (the dispersed phase) is dispersed in the other (the continuous phase). Examples of emulsions include vinaigrettes, milk, mayonnaise, and some cutting fluids for metal working. The photo-sensitive side of photographic film is also an example of a colloid. The word “emulsion” comes from the Latin word for “to milk”, as milk is (among other things) an emulsion of milk fat and water.
Explanation :
The rusting of iron is an electrochemical process that begins with the transfer of electrons from iron to oxygen. The rate of corrosion is affected by water and accelerated by electrolytes, as illustrated by the effects of road salt on the corrosion of automobiles. When impure (cast) iron is in contact with water, oxygen, or other strong oxidants, or acids, it rusts.
[22] German silver used for making utensils is an alloy of –
A.
Copper, silver, nickel
B.
Copper, zinc, nickel
C.
copper, zinc, aluminium
D.
copper, nickel, aluminium
Ans:
Copper, zinc, nickel
Explanation :
Nickel silver, also known as German silver, Argentan, new silver, nickel brass, albata, alpacca, or electrum, is a copper alloy with nickel and often zinc. The usual formulation is 60% copper, 20% nickel and 20% zinc. Nickel silver is named for its silvery appearance, but it contains no elemental silver unless plated. The name "German silver" refers to its development by 19th-century German metalworkers in imitation of the Chinese alloy known as paktong.
[23] Sour milk contains –
A.
acetic acid
B.
tartaric acid
C.
citric acid
D.
lactic acid
Ans:
lactic acid
Explanation :
Lactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3. Lactic acid is found primarily in sour milk products, such as koumiss, laban, yogurt, kefir, and some cottage cheeses. The casein in fermented milk is coagulated (curdled) by lactic acid.
[24] The acid used in lead storage cells is –
A.
phosphoric acid
B.
hydrochloric acid
C.
nitric acid
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Lead-acid batteries, invented in 1859 by French physicist Gaston Plante, are the oldest type of rechargeable battery. Despite having a very low energy-to-weight ratio and a low energy-to-volume ratio, their ability to supply high surge currents means that the cells maintain a relatively large power- to-weight ratio. These features, along with their low cost, make them attractive for use in motor vehicles to provide the high current required by automobile starter motors.
[25] Milk is an example of -
A.
suspension
B.
true solution
C.
emulsion
D.
gel
Ans:
emulsion
Explanation :
An emulsion is a mixture of two or more liquids that are normally immiscible (nonmixable or unblendable). Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion should be used when both the dispersed and the continuous phase are liquids. In an emulsion, one liquid (the dispersed phase) is dispersed in the other (the continuous phase). Examples of emulsions include vinaigrettes, milk, mayonnaise, and some cutting fluids for metal working. The photo-sensitive side of photographic film is also an example of a colloid. The word “emulsion” comes from the Latin word for “to milk”, as milk is (among other things) an emulsion of milk fat and water.
Explanation :
Lactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3. Lactic acid is found primarily in sour milk products, such as koumiss, laban, yogurt, kefir, and some cottage cheeses. The casein in fermented milk is coagulated (curdled) by lactic acid.
[24] The acid used in lead storage cells is –
A.
phosphoric acid
B.
hydrochloric acid
C.
nitric acid
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Lead-acid batteries, invented in 1859 by French physicist Gaston Plante, are the oldest type of rechargeable battery. Despite having a very low energy-to-weight ratio and a low energy-to-volume ratio, their ability to supply high surge currents means that the cells maintain a relatively large power- to-weight ratio. These features, along with their low cost, make them attractive for use in motor vehicles to provide the high current required by automobile starter motors.
[25] Milk is an example of -
A.
suspension
B.
true solution
C.
emulsion
D.
gel
Ans:
emulsion
Explanation :
An emulsion is a mixture of two or more liquids that are normally immiscible (nonmixable or unblendable). Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion should be used when both the dispersed and the continuous phase are liquids. In an emulsion, one liquid (the dispersed phase) is dispersed in the other (the continuous phase). Examples of emulsions include vinaigrettes, milk, mayonnaise, and some cutting fluids for metal working. The photo-sensitive side of photographic film is also an example of a colloid. The word “emulsion” comes from the Latin word for “to milk”, as milk is (among other things) an emulsion of milk fat and water.
Explanation :
An emulsion is a mixture of two or more liquids that are normally immiscible (nonmixable or unblendable). Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion should be used when both the dispersed and the continuous phase are liquids. In an emulsion, one liquid (the dispersed phase) is dispersed in the other (the continuous phase). Examples of emulsions include vinaigrettes, milk, mayonnaise, and some cutting fluids for metal working. The photo-sensitive side of photographic film is also an example of a colloid. The word “emulsion” comes from the Latin word for “to milk”, as milk is (among other things) an emulsion of milk fat and water.