[1] What is the chemical name for `Baking Soda'?
A.
Sodium carbonate
B.
Sodium bicarbonate
C.
Sodium nitrite
D.
Sodium nitrate
Ans:
Sodium bicarbonate
Explanation :
Sodium bicarbonate or sodium hydrogen carbonate is the chemical compound with the formula NaHCO3. Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder. It has a slightly salty, alkaline taste resembling that of washing soda (sodium carbonate).
[2] The first metal used by a man was –
A.
Copper
B.
Silver
C.
Bronze
D.
Brass
Ans:
Copper
Explanation :
Copper occurs naturally as native copper and was known to some of the oldest civilizations on record. It has a history of use that is at least 10,000 years old, and estimates of its discovery place it at 9000 BC in the Middle East; a copper pendant was found in northern Iraq that dates to 8700 BC. There is evidence that gold and meteoric iron (but not iron smelting) were the only metals used by humans before copper.
[3] Which of the following is used to remove rust stains on cloth?
A.
Kerosene
B.
Lime
C.
Oxalic acid solution
D.
Petrol
Ans:
Oxalic acid solution
Explanation :
Oxalic acid is an organic compound with the formula H2C2O2. It is a colourless crystalline solid that dissolves in water to give colourless solutions. It is classified as a dicarboxylic acid. In terms of acid strength. it is much stronger than acetic acid. Oxalic acid is a reducing agent and its conjugate base, known as oxalate, is a chelating agent for metal cations.
[4] The substance most commonly used as a food preservative is –
A.
sodium carbonate
B.
tartaric acid
C.
acetic acid
D.
sodium salt of benzoic acid
Ans:
sodium salt of benzoic acid
Explanation :
A preservative is a naturally occurring or synthetically produced substance that is added to products such as foods, pharmaceuticals, paints, biological samples, wood, etc. to prevent decomposition by microbial growth or by undesirable chemical changes. Preservative food additives can be used alone or in conjunction with other methods of food preservation. Preservatives may be antimicrobial preservatives, which inhibit the growth of bacteria or fungi, including mold or they can be antioxidants such as oxygen absorbers, which inhibit the oxidation of food constituents.
[5] What among following is used to produce artificial rain?
A.
copper oxide
B.
carbon monoxide
C.
silver iodide
D.
silver nitrate
Ans:
silver iodide
Explanation :
Artificial rain is produced by spraying clouds with substances like Silver Iodide (costly) or cheaper ones like solid carbon dioxide (dry ice) or even finely powdered Sodium Chloride.
[6] Detergents clean surfaces on the principle of –
A.
viscosity
B.
surface tension
C.
elasticity
D.
floatation
Ans:
surface tension
Explanation :
Detergents and soaps are used for cleaning because pure water can't remove oily, organic soiling. Soap cleans by acting as an emulsifier. Basically, soap allows oil and water to mix so that oily grime can be removed during rinsing. Detergents were developed in response to the shortage of the animal and vegetable fats used to make soap during World War I and World War II. Detergents are primarily surfactants, which could be produced easily from petrochemicals.
[7] Which of the following is ozone depleting pesticide?
A.
D.D.T.
B.
Benzene
C.
Methyl bromide
D.
Ethylene ozonide
Ans:
Methyl bromide
Explanation :
Methyl bromide- is considered to be a significant ozone depleting substance (ODS) by atmospheric scientists. While methyl bromide is a natural substance, the additional methyl bromide added to the atmosphere by humans contributes to the thinning of the ozone layer, allowing increased UV radiation to reach the earth's surface, with potential impact not only to human health and the environment, but to agricultural crops as well.
[8] Galvanised iron is made by coating iron with –
A.
Zinc
B.
Nickel
C.
Chromium
D.
Sulphur
Ans:
Zinc
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.
[9] An atomic pile is used for –
A.
producing X-rays
B.
conducting nuclear fission
C.
conducting thermonuclear fusion
D.
accelerating atoms
Ans:
conducting nuclear fission
Explanation :
An atomic pile is a nuclear reactor that uses controlled nuclear fission to generate energy. The most common reactor consists of a large assembly of graphite (an allotropic form of carbon) blocks having rods of uranium metal (fuel).
[10] Which of the following type of coal has the lowest proportion of volatile matter?
A.
Lignite
B.
Peat
C.
Bituminous
D.
Anthracite
Ans:
Anthracite
Explanation :
Anthracite has the lowest proportion of volatile matter. Volatile matter in coal refers to the components of coal, except for moisture, which are liberated at high temperature in the absence of air. This is usually a mixture of short and long chain hydrocarbons, aromatic hydrocarbons and some sulfur. The volatile matter of coal is determined under rigidly controlled standards.
[11] The compound to which H2 does not add is –
A.
Biphenyl ethylene
B.
Tetraphenyl ethylene
C.
Tetra - a - naphthylethylene
D.
Tetra - 9 - phenanthrylethylene
Ans:
Tetraphenyl ethylene
Explanation :
While H2 is not very reactive under standard conditions, it does form compounds with most elements. Millions of hydrocarbons are known, but they are not formed by the direct reaction of elementary hydrogen and carbon. Hydrogen can form compounds with elements that are more electronegative, such as halogens. Hydrogen forms a vast array of compounds with carbon.
[12] Major gaseous pollutant of the thermal power station is –
A.
H2S
B.
NH3
C.
NO2
D.
SO2
Ans:
SO2
Explanation :
A flue-gas stack is a type of chimney, a vertical pipe, channel or similar structure through which combustion product gases called flue gases are exhausted to the outside air. Flue gases are produced when coal, oil, natural gas, wood or any other fuel is combusted in an industrial furnace, a power plant's steam-generating boiler, or other large combustion device. Flue was is usually composed of carbon dioxide (CO2) and water vapor as well as nitrogen and excess oxygen remaining from the intake combustion air.
[13] The process of removing calcium and magnesium from hard water is known as –
A.
Sedimentation
B.
Filtration
C.
Flocculation
D.
Water softening
Ans:
Water softening
Explanation :
Water softening is the reduction of the concentration of calcium, magnesium, and certain other metal cations in hard water. Hardness ions dissolved in water can cause a variety of undesired effects including interfering with the action of soaps, the buildup of limescale, which can foul plumbing, and galvanic corrosion. Conventional water-softening appliances intended for household use depend on an ion-exchange resin in which hardness ions are exchanged for sodium ions. Water softening may be desirable where the source of water is hard. However, hard water also conveys some benefits to health by reducing the solubility of potentially toxic metal ions such as lead and copper.
[14] Which of the following metals causes Itai-Itai disease?
A.
Cadmium
B.
Chromium
C.
Cobalt
D.
Copper
Ans:
Cadmium
Explanation :
Itai-itai disease was the documented case of mass cadmium poisoning in Toyama Prefecture, Japan, starting around 1912. The cadmium poisoning caused softening of the bones and kidney failure. The disease is named for the severe pains caused in the joints and spine. The cadmium was released into rivers by mining companies in the mountains. The mining companies were successfully sued for the damage. Itai-itai disease is known as one of the Four Big Pollution Diseases of Japan.
[15] Which is used in preparation of dynamite?
A.
glycerol
B.
ethyl alcohol
C.
methyl alcohol
D.
glycol
Ans:
glycerol
Explanation :
Dynamite is an explosive made of nitroglycerin, sorbents (such as powdered shells or clay) and stabilizers. It was invented by the Swedish chemist and engineer Alfred Nobel in Geesthacht, and patented in 1867.
[16] Vinegar is the trade name of -
A.
acetic acid
B.
chloroform
C.
carbon tetrachloride
D.
ethyl alcohol
Ans:
acetic acid
Explanation :
The trivial name acetic acid is the most commonly used and preferred IUPAC name. The systematic name ethanoic acid, a valid IUPAC name, is constructed according to the substitutive nomenclature.
[17] Acid secretion is characteristic of -
A.
Buccal cavity
B.
Stomach
C.
Small intestine
D.
Large intestine
Ans:
Stomach
Explanation :
The stomach is famous for its secretion of hydrochloric acid. It is secreted from parietal cells into the lumen where it establishes an extremely acidic environment. This acid is important for activation of pepsinogen and inactivation of ingested microorganisms such as bacteria.
[18] Which one of the following is not a fertilizer?
A.
Ammonium sulphate
B.
Calcium sulphate
C.
Calcium ammonium nitrate
D.
Potassium nitrate
Ans:
Calcium sulphate
Explanation :
Calcium sulfate is a common laboratory and industrial chemical. In the form of -anhydrite (the nearly anhydrous form), it is used as a desiccant. It is also used as a coagulant in products like tofu. The main sources of calcium sulfate are naturally occurring gypsum and anhydrite which occur at many locations worldwide as evaporites.
[19] The common refrigerant in domestic refrigerator is -
A.
Neon
B.
Oxygen
C.
Nitrogen
D.
Freon
Ans:
Freon
Explanation :
Common refrigerants used in domestic refrigerators are freon, neon and nitrogen. It flows through four components of refrigerator again and again. These four components are cooling chamber, compressor, heat exchanger and expander
[20] The chemical name of “laughing gas” is -
A.
Nitric oxide
B.
Nitrogen dioxide
C.
Nitrogen pentoxide
D.
Nitrous oxide
Ans:
Nitrous oxide
Explanation :
Nitrous oxide, commonly known as laughing gas, is a chemical compound with the formula N2O. It is used in surgery and dentistry for its anesthetic and analgesic effects. It is known as "laughing gas" due to the euphoric effects of inhaling it, a property that has led to its recreational use as a dissociative anesthetic.
[21] Which of the following is used to remove ink and rust stains on cloth?
A.
Oxalic acid
B.
Alcohol
C.
Ether
D.
Kerosene oil
Ans:
Oxalic acid
Explanation :
Oxalic acid is a reducing agent and its conjugate base, known as oxalate, is a chelating agent for metal cations and stain removal. Oxalic acid's main applications include cleaning or bleaching, removal of stains on clothes and the removal of rust.
[22] Bleaching action of chlorine is by -
A.
decomposition
B.
hydrolysis
C.
reduction
D.
oxidation
Ans:
oxidation
Explanation :
Chlorine bleaches by the process of oxidation. It needs moisture for its bleaching action. Chlorine reacts with water to form hydrochloric and hypochlorous acids.
[23] Hardest material is -
A.
Tungsten
B.
Diamond
C.
Steel
D.
Graphite
Ans:
Diamond
Explanation :
Diamondsare commonly known as the hardest substance on earth, used in drill bits for cutting applications. Diamond is currently thought to be the hardest natural material on Earth, having a hardness of ten out of ten on the Mohs scale of mineral hardness. Diamond is made up of carbon atoms which share strong covalent bonds (where electrons are shared between atoms) and are equally spaced in a lattice arrangement.
[24] When iron rusts, its weight -
A.
decreases
B.
increases
C.
Constant
D.
None
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[25] Which of the following is not a donor atom?
A.
Phosphorus
B.
Antimony
C.
Arsenic
D.
Aluminium
Ans:
Aluminium
Explanation :
Aluminium is an acceptor atom, an impurity atom in a semiconductor, which can accept or take up one or more electrons from the crystal and become negatively charged.
Explanation :
Sodium bicarbonate or sodium hydrogen carbonate is the chemical compound with the formula NaHCO3. Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder. It has a slightly salty, alkaline taste resembling that of washing soda (sodium carbonate).
[2] The first metal used by a man was –
A.
Copper
B.
Silver
C.
Bronze
D.
Brass
Ans:
Copper
Explanation :
Copper occurs naturally as native copper and was known to some of the oldest civilizations on record. It has a history of use that is at least 10,000 years old, and estimates of its discovery place it at 9000 BC in the Middle East; a copper pendant was found in northern Iraq that dates to 8700 BC. There is evidence that gold and meteoric iron (but not iron smelting) were the only metals used by humans before copper.
[3] Which of the following is used to remove rust stains on cloth?
A.
Kerosene
B.
Lime
C.
Oxalic acid solution
D.
Petrol
Ans:
Oxalic acid solution
Explanation :
Oxalic acid is an organic compound with the formula H2C2O2. It is a colourless crystalline solid that dissolves in water to give colourless solutions. It is classified as a dicarboxylic acid. In terms of acid strength. it is much stronger than acetic acid. Oxalic acid is a reducing agent and its conjugate base, known as oxalate, is a chelating agent for metal cations.
[4] The substance most commonly used as a food preservative is –
A.
sodium carbonate
B.
tartaric acid
C.
acetic acid
D.
sodium salt of benzoic acid
Ans:
sodium salt of benzoic acid
Explanation :
A preservative is a naturally occurring or synthetically produced substance that is added to products such as foods, pharmaceuticals, paints, biological samples, wood, etc. to prevent decomposition by microbial growth or by undesirable chemical changes. Preservative food additives can be used alone or in conjunction with other methods of food preservation. Preservatives may be antimicrobial preservatives, which inhibit the growth of bacteria or fungi, including mold or they can be antioxidants such as oxygen absorbers, which inhibit the oxidation of food constituents.
[5] What among following is used to produce artificial rain?
A.
copper oxide
B.
carbon monoxide
C.
silver iodide
D.
silver nitrate
Ans:
silver iodide
Explanation :
Artificial rain is produced by spraying clouds with substances like Silver Iodide (costly) or cheaper ones like solid carbon dioxide (dry ice) or even finely powdered Sodium Chloride.
[6] Detergents clean surfaces on the principle of –
A.
viscosity
B.
surface tension
C.
elasticity
D.
floatation
Ans:
surface tension
Explanation :
Detergents and soaps are used for cleaning because pure water can't remove oily, organic soiling. Soap cleans by acting as an emulsifier. Basically, soap allows oil and water to mix so that oily grime can be removed during rinsing. Detergents were developed in response to the shortage of the animal and vegetable fats used to make soap during World War I and World War II. Detergents are primarily surfactants, which could be produced easily from petrochemicals.
[7] Which of the following is ozone depleting pesticide?
A.
D.D.T.
B.
Benzene
C.
Methyl bromide
D.
Ethylene ozonide
Ans:
Methyl bromide
Explanation :
Methyl bromide- is considered to be a significant ozone depleting substance (ODS) by atmospheric scientists. While methyl bromide is a natural substance, the additional methyl bromide added to the atmosphere by humans contributes to the thinning of the ozone layer, allowing increased UV radiation to reach the earth's surface, with potential impact not only to human health and the environment, but to agricultural crops as well.
[8] Galvanised iron is made by coating iron with –
A.
Zinc
B.
Nickel
C.
Chromium
D.
Sulphur
Ans:
Zinc
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.
[9] An atomic pile is used for –
A.
producing X-rays
B.
conducting nuclear fission
C.
conducting thermonuclear fusion
D.
accelerating atoms
Ans:
conducting nuclear fission
Explanation :
An atomic pile is a nuclear reactor that uses controlled nuclear fission to generate energy. The most common reactor consists of a large assembly of graphite (an allotropic form of carbon) blocks having rods of uranium metal (fuel).
[10] Which of the following type of coal has the lowest proportion of volatile matter?
A.
Lignite
B.
Peat
C.
Bituminous
D.
Anthracite
Ans:
Anthracite
Explanation :
Anthracite has the lowest proportion of volatile matter. Volatile matter in coal refers to the components of coal, except for moisture, which are liberated at high temperature in the absence of air. This is usually a mixture of short and long chain hydrocarbons, aromatic hydrocarbons and some sulfur. The volatile matter of coal is determined under rigidly controlled standards.
[11] The compound to which H2 does not add is –
A.
Biphenyl ethylene
B.
Tetraphenyl ethylene
C.
Tetra - a - naphthylethylene
D.
Tetra - 9 - phenanthrylethylene
Ans:
Tetraphenyl ethylene
Explanation :
While H2 is not very reactive under standard conditions, it does form compounds with most elements. Millions of hydrocarbons are known, but they are not formed by the direct reaction of elementary hydrogen and carbon. Hydrogen can form compounds with elements that are more electronegative, such as halogens. Hydrogen forms a vast array of compounds with carbon.
[12] Major gaseous pollutant of the thermal power station is –
A.
H2S
B.
NH3
C.
NO2
D.
SO2
Ans:
SO2
Explanation :
A flue-gas stack is a type of chimney, a vertical pipe, channel or similar structure through which combustion product gases called flue gases are exhausted to the outside air. Flue gases are produced when coal, oil, natural gas, wood or any other fuel is combusted in an industrial furnace, a power plant's steam-generating boiler, or other large combustion device. Flue was is usually composed of carbon dioxide (CO2) and water vapor as well as nitrogen and excess oxygen remaining from the intake combustion air.
[13] The process of removing calcium and magnesium from hard water is known as –
A.
Sedimentation
B.
Filtration
C.
Flocculation
D.
Water softening
Ans:
Water softening
Explanation :
Water softening is the reduction of the concentration of calcium, magnesium, and certain other metal cations in hard water. Hardness ions dissolved in water can cause a variety of undesired effects including interfering with the action of soaps, the buildup of limescale, which can foul plumbing, and galvanic corrosion. Conventional water-softening appliances intended for household use depend on an ion-exchange resin in which hardness ions are exchanged for sodium ions. Water softening may be desirable where the source of water is hard. However, hard water also conveys some benefits to health by reducing the solubility of potentially toxic metal ions such as lead and copper.
[14] Which of the following metals causes Itai-Itai disease?
A.
Cadmium
B.
Chromium
C.
Cobalt
D.
Copper
Ans:
Cadmium
Explanation :
Itai-itai disease was the documented case of mass cadmium poisoning in Toyama Prefecture, Japan, starting around 1912. The cadmium poisoning caused softening of the bones and kidney failure. The disease is named for the severe pains caused in the joints and spine. The cadmium was released into rivers by mining companies in the mountains. The mining companies were successfully sued for the damage. Itai-itai disease is known as one of the Four Big Pollution Diseases of Japan.
[15] Which is used in preparation of dynamite?
A.
glycerol
B.
ethyl alcohol
C.
methyl alcohol
D.
glycol
Ans:
glycerol
Explanation :
Dynamite is an explosive made of nitroglycerin, sorbents (such as powdered shells or clay) and stabilizers. It was invented by the Swedish chemist and engineer Alfred Nobel in Geesthacht, and patented in 1867.
[16] Vinegar is the trade name of -
A.
acetic acid
B.
chloroform
C.
carbon tetrachloride
D.
ethyl alcohol
Ans:
acetic acid
Explanation :
The trivial name acetic acid is the most commonly used and preferred IUPAC name. The systematic name ethanoic acid, a valid IUPAC name, is constructed according to the substitutive nomenclature.
[17] Acid secretion is characteristic of -
A.
Buccal cavity
B.
Stomach
C.
Small intestine
D.
Large intestine
Ans:
Stomach
Explanation :
The stomach is famous for its secretion of hydrochloric acid. It is secreted from parietal cells into the lumen where it establishes an extremely acidic environment. This acid is important for activation of pepsinogen and inactivation of ingested microorganisms such as bacteria.
[18] Which one of the following is not a fertilizer?
A.
Ammonium sulphate
B.
Calcium sulphate
C.
Calcium ammonium nitrate
D.
Potassium nitrate
Ans:
Calcium sulphate
Explanation :
Calcium sulfate is a common laboratory and industrial chemical. In the form of -anhydrite (the nearly anhydrous form), it is used as a desiccant. It is also used as a coagulant in products like tofu. The main sources of calcium sulfate are naturally occurring gypsum and anhydrite which occur at many locations worldwide as evaporites.
[19] The common refrigerant in domestic refrigerator is -
A.
Neon
B.
Oxygen
C.
Nitrogen
D.
Freon
Ans:
Freon
Explanation :
Common refrigerants used in domestic refrigerators are freon, neon and nitrogen. It flows through four components of refrigerator again and again. These four components are cooling chamber, compressor, heat exchanger and expander
[20] The chemical name of “laughing gas” is -
A.
Nitric oxide
B.
Nitrogen dioxide
C.
Nitrogen pentoxide
D.
Nitrous oxide
Ans:
Nitrous oxide
Explanation :
Nitrous oxide, commonly known as laughing gas, is a chemical compound with the formula N2O. It is used in surgery and dentistry for its anesthetic and analgesic effects. It is known as "laughing gas" due to the euphoric effects of inhaling it, a property that has led to its recreational use as a dissociative anesthetic.
[21] Which of the following is used to remove ink and rust stains on cloth?
A.
Oxalic acid
B.
Alcohol
C.
Ether
D.
Kerosene oil
Ans:
Oxalic acid
Explanation :
Oxalic acid is a reducing agent and its conjugate base, known as oxalate, is a chelating agent for metal cations and stain removal. Oxalic acid's main applications include cleaning or bleaching, removal of stains on clothes and the removal of rust.
[22] Bleaching action of chlorine is by -
A.
decomposition
B.
hydrolysis
C.
reduction
D.
oxidation
Ans:
oxidation
Explanation :
Chlorine bleaches by the process of oxidation. It needs moisture for its bleaching action. Chlorine reacts with water to form hydrochloric and hypochlorous acids.
[23] Hardest material is -
A.
Tungsten
B.
Diamond
C.
Steel
D.
Graphite
Ans:
Diamond
Explanation :
Diamondsare commonly known as the hardest substance on earth, used in drill bits for cutting applications. Diamond is currently thought to be the hardest natural material on Earth, having a hardness of ten out of ten on the Mohs scale of mineral hardness. Diamond is made up of carbon atoms which share strong covalent bonds (where electrons are shared between atoms) and are equally spaced in a lattice arrangement.
[24] When iron rusts, its weight -
A.
decreases
B.
increases
C.
Constant
D.
None
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[25] Which of the following is not a donor atom?
A.
Phosphorus
B.
Antimony
C.
Arsenic
D.
Aluminium
Ans:
Aluminium
Explanation :
Aluminium is an acceptor atom, an impurity atom in a semiconductor, which can accept or take up one or more electrons from the crystal and become negatively charged.
Explanation :
Oxalic acid is an organic compound with the formula H2C2O2. It is a colourless crystalline solid that dissolves in water to give colourless solutions. It is classified as a dicarboxylic acid. In terms of acid strength. it is much stronger than acetic acid. Oxalic acid is a reducing agent and its conjugate base, known as oxalate, is a chelating agent for metal cations.
[4] The substance most commonly used as a food preservative is –
A.
sodium carbonate
B.
tartaric acid
C.
acetic acid
D.
sodium salt of benzoic acid
Ans:
sodium salt of benzoic acid
Explanation :
A preservative is a naturally occurring or synthetically produced substance that is added to products such as foods, pharmaceuticals, paints, biological samples, wood, etc. to prevent decomposition by microbial growth or by undesirable chemical changes. Preservative food additives can be used alone or in conjunction with other methods of food preservation. Preservatives may be antimicrobial preservatives, which inhibit the growth of bacteria or fungi, including mold or they can be antioxidants such as oxygen absorbers, which inhibit the oxidation of food constituents.
[5] What among following is used to produce artificial rain?
A.
copper oxide
B.
carbon monoxide
C.
silver iodide
D.
silver nitrate
Ans:
silver iodide
Explanation :
Artificial rain is produced by spraying clouds with substances like Silver Iodide (costly) or cheaper ones like solid carbon dioxide (dry ice) or even finely powdered Sodium Chloride.
[6] Detergents clean surfaces on the principle of –
A.
viscosity
B.
surface tension
C.
elasticity
D.
floatation
Ans:
surface tension
Explanation :
Detergents and soaps are used for cleaning because pure water can't remove oily, organic soiling. Soap cleans by acting as an emulsifier. Basically, soap allows oil and water to mix so that oily grime can be removed during rinsing. Detergents were developed in response to the shortage of the animal and vegetable fats used to make soap during World War I and World War II. Detergents are primarily surfactants, which could be produced easily from petrochemicals.
[7] Which of the following is ozone depleting pesticide?
A.
D.D.T.
B.
Benzene
C.
Methyl bromide
D.
Ethylene ozonide
Ans:
Methyl bromide
Explanation :
Methyl bromide- is considered to be a significant ozone depleting substance (ODS) by atmospheric scientists. While methyl bromide is a natural substance, the additional methyl bromide added to the atmosphere by humans contributes to the thinning of the ozone layer, allowing increased UV radiation to reach the earth's surface, with potential impact not only to human health and the environment, but to agricultural crops as well.
[8] Galvanised iron is made by coating iron with –
A.
Zinc
B.
Nickel
C.
Chromium
D.
Sulphur
Ans:
Zinc
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.
[9] An atomic pile is used for –
A.
producing X-rays
B.
conducting nuclear fission
C.
conducting thermonuclear fusion
D.
accelerating atoms
Ans:
conducting nuclear fission
Explanation :
An atomic pile is a nuclear reactor that uses controlled nuclear fission to generate energy. The most common reactor consists of a large assembly of graphite (an allotropic form of carbon) blocks having rods of uranium metal (fuel).
[10] Which of the following type of coal has the lowest proportion of volatile matter?
A.
Lignite
B.
Peat
C.
Bituminous
D.
Anthracite
Ans:
Anthracite
Explanation :
Anthracite has the lowest proportion of volatile matter. Volatile matter in coal refers to the components of coal, except for moisture, which are liberated at high temperature in the absence of air. This is usually a mixture of short and long chain hydrocarbons, aromatic hydrocarbons and some sulfur. The volatile matter of coal is determined under rigidly controlled standards.
[11] The compound to which H2 does not add is –
A.
Biphenyl ethylene
B.
Tetraphenyl ethylene
C.
Tetra - a - naphthylethylene
D.
Tetra - 9 - phenanthrylethylene
Ans:
Tetraphenyl ethylene
Explanation :
While H2 is not very reactive under standard conditions, it does form compounds with most elements. Millions of hydrocarbons are known, but they are not formed by the direct reaction of elementary hydrogen and carbon. Hydrogen can form compounds with elements that are more electronegative, such as halogens. Hydrogen forms a vast array of compounds with carbon.
[12] Major gaseous pollutant of the thermal power station is –
A.
H2S
B.
NH3
C.
NO2
D.
SO2
Ans:
SO2
Explanation :
A flue-gas stack is a type of chimney, a vertical pipe, channel or similar structure through which combustion product gases called flue gases are exhausted to the outside air. Flue gases are produced when coal, oil, natural gas, wood or any other fuel is combusted in an industrial furnace, a power plant's steam-generating boiler, or other large combustion device. Flue was is usually composed of carbon dioxide (CO2) and water vapor as well as nitrogen and excess oxygen remaining from the intake combustion air.
[13] The process of removing calcium and magnesium from hard water is known as –
A.
Sedimentation
B.
Filtration
C.
Flocculation
D.
Water softening
Ans:
Water softening
Explanation :
Water softening is the reduction of the concentration of calcium, magnesium, and certain other metal cations in hard water. Hardness ions dissolved in water can cause a variety of undesired effects including interfering with the action of soaps, the buildup of limescale, which can foul plumbing, and galvanic corrosion. Conventional water-softening appliances intended for household use depend on an ion-exchange resin in which hardness ions are exchanged for sodium ions. Water softening may be desirable where the source of water is hard. However, hard water also conveys some benefits to health by reducing the solubility of potentially toxic metal ions such as lead and copper.
[14] Which of the following metals causes Itai-Itai disease?
A.
Cadmium
B.
Chromium
C.
Cobalt
D.
Copper
Ans:
Cadmium
Explanation :
Itai-itai disease was the documented case of mass cadmium poisoning in Toyama Prefecture, Japan, starting around 1912. The cadmium poisoning caused softening of the bones and kidney failure. The disease is named for the severe pains caused in the joints and spine. The cadmium was released into rivers by mining companies in the mountains. The mining companies were successfully sued for the damage. Itai-itai disease is known as one of the Four Big Pollution Diseases of Japan.
[15] Which is used in preparation of dynamite?
A.
glycerol
B.
ethyl alcohol
C.
methyl alcohol
D.
glycol
Ans:
glycerol
Explanation :
Dynamite is an explosive made of nitroglycerin, sorbents (such as powdered shells or clay) and stabilizers. It was invented by the Swedish chemist and engineer Alfred Nobel in Geesthacht, and patented in 1867.
[16] Vinegar is the trade name of -
A.
acetic acid
B.
chloroform
C.
carbon tetrachloride
D.
ethyl alcohol
Ans:
acetic acid
Explanation :
The trivial name acetic acid is the most commonly used and preferred IUPAC name. The systematic name ethanoic acid, a valid IUPAC name, is constructed according to the substitutive nomenclature.
[17] Acid secretion is characteristic of -
A.
Buccal cavity
B.
Stomach
C.
Small intestine
D.
Large intestine
Ans:
Stomach
Explanation :
The stomach is famous for its secretion of hydrochloric acid. It is secreted from parietal cells into the lumen where it establishes an extremely acidic environment. This acid is important for activation of pepsinogen and inactivation of ingested microorganisms such as bacteria.
[18] Which one of the following is not a fertilizer?
A.
Ammonium sulphate
B.
Calcium sulphate
C.
Calcium ammonium nitrate
D.
Potassium nitrate
Ans:
Calcium sulphate
Explanation :
Calcium sulfate is a common laboratory and industrial chemical. In the form of -anhydrite (the nearly anhydrous form), it is used as a desiccant. It is also used as a coagulant in products like tofu. The main sources of calcium sulfate are naturally occurring gypsum and anhydrite which occur at many locations worldwide as evaporites.
[19] The common refrigerant in domestic refrigerator is -
A.
Neon
B.
Oxygen
C.
Nitrogen
D.
Freon
Ans:
Freon
Explanation :
Common refrigerants used in domestic refrigerators are freon, neon and nitrogen. It flows through four components of refrigerator again and again. These four components are cooling chamber, compressor, heat exchanger and expander
[20] The chemical name of “laughing gas” is -
A.
Nitric oxide
B.
Nitrogen dioxide
C.
Nitrogen pentoxide
D.
Nitrous oxide
Ans:
Nitrous oxide
Explanation :
Nitrous oxide, commonly known as laughing gas, is a chemical compound with the formula N2O. It is used in surgery and dentistry for its anesthetic and analgesic effects. It is known as "laughing gas" due to the euphoric effects of inhaling it, a property that has led to its recreational use as a dissociative anesthetic.
[21] Which of the following is used to remove ink and rust stains on cloth?
A.
Oxalic acid
B.
Alcohol
C.
Ether
D.
Kerosene oil
Ans:
Oxalic acid
Explanation :
Oxalic acid is a reducing agent and its conjugate base, known as oxalate, is a chelating agent for metal cations and stain removal. Oxalic acid's main applications include cleaning or bleaching, removal of stains on clothes and the removal of rust.
[22] Bleaching action of chlorine is by -
A.
decomposition
B.
hydrolysis
C.
reduction
D.
oxidation
Ans:
oxidation
Explanation :
Chlorine bleaches by the process of oxidation. It needs moisture for its bleaching action. Chlorine reacts with water to form hydrochloric and hypochlorous acids.
[23] Hardest material is -
A.
Tungsten
B.
Diamond
C.
Steel
D.
Graphite
Ans:
Diamond
Explanation :
Diamondsare commonly known as the hardest substance on earth, used in drill bits for cutting applications. Diamond is currently thought to be the hardest natural material on Earth, having a hardness of ten out of ten on the Mohs scale of mineral hardness. Diamond is made up of carbon atoms which share strong covalent bonds (where electrons are shared between atoms) and are equally spaced in a lattice arrangement.
[24] When iron rusts, its weight -
A.
decreases
B.
increases
C.
Constant
D.
None
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[25] Which of the following is not a donor atom?
A.
Phosphorus
B.
Antimony
C.
Arsenic
D.
Aluminium
Ans:
Aluminium
Explanation :
Aluminium is an acceptor atom, an impurity atom in a semiconductor, which can accept or take up one or more electrons from the crystal and become negatively charged.
Explanation :
Artificial rain is produced by spraying clouds with substances like Silver Iodide (costly) or cheaper ones like solid carbon dioxide (dry ice) or even finely powdered Sodium Chloride.
[6] Detergents clean surfaces on the principle of –
A.
viscosity
B.
surface tension
C.
elasticity
D.
floatation
Ans:
surface tension
Explanation :
Detergents and soaps are used for cleaning because pure water can't remove oily, organic soiling. Soap cleans by acting as an emulsifier. Basically, soap allows oil and water to mix so that oily grime can be removed during rinsing. Detergents were developed in response to the shortage of the animal and vegetable fats used to make soap during World War I and World War II. Detergents are primarily surfactants, which could be produced easily from petrochemicals.
[7] Which of the following is ozone depleting pesticide?
A.
D.D.T.
B.
Benzene
C.
Methyl bromide
D.
Ethylene ozonide
Ans:
Methyl bromide
Explanation :
Methyl bromide- is considered to be a significant ozone depleting substance (ODS) by atmospheric scientists. While methyl bromide is a natural substance, the additional methyl bromide added to the atmosphere by humans contributes to the thinning of the ozone layer, allowing increased UV radiation to reach the earth's surface, with potential impact not only to human health and the environment, but to agricultural crops as well.
[8] Galvanised iron is made by coating iron with –
A.
Zinc
B.
Nickel
C.
Chromium
D.
Sulphur
Ans:
Zinc
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.
[9] An atomic pile is used for –
A.
producing X-rays
B.
conducting nuclear fission
C.
conducting thermonuclear fusion
D.
accelerating atoms
Ans:
conducting nuclear fission
Explanation :
An atomic pile is a nuclear reactor that uses controlled nuclear fission to generate energy. The most common reactor consists of a large assembly of graphite (an allotropic form of carbon) blocks having rods of uranium metal (fuel).
[10] Which of the following type of coal has the lowest proportion of volatile matter?
A.
Lignite
B.
Peat
C.
Bituminous
D.
Anthracite
Ans:
Anthracite
Explanation :
Anthracite has the lowest proportion of volatile matter. Volatile matter in coal refers to the components of coal, except for moisture, which are liberated at high temperature in the absence of air. This is usually a mixture of short and long chain hydrocarbons, aromatic hydrocarbons and some sulfur. The volatile matter of coal is determined under rigidly controlled standards.
[11] The compound to which H2 does not add is –
A.
Biphenyl ethylene
B.
Tetraphenyl ethylene
C.
Tetra - a - naphthylethylene
D.
Tetra - 9 - phenanthrylethylene
Ans:
Tetraphenyl ethylene
Explanation :
While H2 is not very reactive under standard conditions, it does form compounds with most elements. Millions of hydrocarbons are known, but they are not formed by the direct reaction of elementary hydrogen and carbon. Hydrogen can form compounds with elements that are more electronegative, such as halogens. Hydrogen forms a vast array of compounds with carbon.
[12] Major gaseous pollutant of the thermal power station is –
A.
H2S
B.
NH3
C.
NO2
D.
SO2
Ans:
SO2
Explanation :
A flue-gas stack is a type of chimney, a vertical pipe, channel or similar structure through which combustion product gases called flue gases are exhausted to the outside air. Flue gases are produced when coal, oil, natural gas, wood or any other fuel is combusted in an industrial furnace, a power plant's steam-generating boiler, or other large combustion device. Flue was is usually composed of carbon dioxide (CO2) and water vapor as well as nitrogen and excess oxygen remaining from the intake combustion air.
[13] The process of removing calcium and magnesium from hard water is known as –
A.
Sedimentation
B.
Filtration
C.
Flocculation
D.
Water softening
Ans:
Water softening
Explanation :
Water softening is the reduction of the concentration of calcium, magnesium, and certain other metal cations in hard water. Hardness ions dissolved in water can cause a variety of undesired effects including interfering with the action of soaps, the buildup of limescale, which can foul plumbing, and galvanic corrosion. Conventional water-softening appliances intended for household use depend on an ion-exchange resin in which hardness ions are exchanged for sodium ions. Water softening may be desirable where the source of water is hard. However, hard water also conveys some benefits to health by reducing the solubility of potentially toxic metal ions such as lead and copper.
[14] Which of the following metals causes Itai-Itai disease?
A.
Cadmium
B.
Chromium
C.
Cobalt
D.
Copper
Ans:
Cadmium
Explanation :
Itai-itai disease was the documented case of mass cadmium poisoning in Toyama Prefecture, Japan, starting around 1912. The cadmium poisoning caused softening of the bones and kidney failure. The disease is named for the severe pains caused in the joints and spine. The cadmium was released into rivers by mining companies in the mountains. The mining companies were successfully sued for the damage. Itai-itai disease is known as one of the Four Big Pollution Diseases of Japan.
[15] Which is used in preparation of dynamite?
A.
glycerol
B.
ethyl alcohol
C.
methyl alcohol
D.
glycol
Ans:
glycerol
Explanation :
Dynamite is an explosive made of nitroglycerin, sorbents (such as powdered shells or clay) and stabilizers. It was invented by the Swedish chemist and engineer Alfred Nobel in Geesthacht, and patented in 1867.
[16] Vinegar is the trade name of -
A.
acetic acid
B.
chloroform
C.
carbon tetrachloride
D.
ethyl alcohol
Ans:
acetic acid
Explanation :
The trivial name acetic acid is the most commonly used and preferred IUPAC name. The systematic name ethanoic acid, a valid IUPAC name, is constructed according to the substitutive nomenclature.
[17] Acid secretion is characteristic of -
A.
Buccal cavity
B.
Stomach
C.
Small intestine
D.
Large intestine
Ans:
Stomach
Explanation :
The stomach is famous for its secretion of hydrochloric acid. It is secreted from parietal cells into the lumen where it establishes an extremely acidic environment. This acid is important for activation of pepsinogen and inactivation of ingested microorganisms such as bacteria.
[18] Which one of the following is not a fertilizer?
A.
Ammonium sulphate
B.
Calcium sulphate
C.
Calcium ammonium nitrate
D.
Potassium nitrate
Ans:
Calcium sulphate
Explanation :
Calcium sulfate is a common laboratory and industrial chemical. In the form of -anhydrite (the nearly anhydrous form), it is used as a desiccant. It is also used as a coagulant in products like tofu. The main sources of calcium sulfate are naturally occurring gypsum and anhydrite which occur at many locations worldwide as evaporites.
[19] The common refrigerant in domestic refrigerator is -
A.
Neon
B.
Oxygen
C.
Nitrogen
D.
Freon
Ans:
Freon
Explanation :
Common refrigerants used in domestic refrigerators are freon, neon and nitrogen. It flows through four components of refrigerator again and again. These four components are cooling chamber, compressor, heat exchanger and expander
[20] The chemical name of “laughing gas” is -
A.
Nitric oxide
B.
Nitrogen dioxide
C.
Nitrogen pentoxide
D.
Nitrous oxide
Ans:
Nitrous oxide
Explanation :
Nitrous oxide, commonly known as laughing gas, is a chemical compound with the formula N2O. It is used in surgery and dentistry for its anesthetic and analgesic effects. It is known as "laughing gas" due to the euphoric effects of inhaling it, a property that has led to its recreational use as a dissociative anesthetic.
[21] Which of the following is used to remove ink and rust stains on cloth?
A.
Oxalic acid
B.
Alcohol
C.
Ether
D.
Kerosene oil
Ans:
Oxalic acid
Explanation :
Oxalic acid is a reducing agent and its conjugate base, known as oxalate, is a chelating agent for metal cations and stain removal. Oxalic acid's main applications include cleaning or bleaching, removal of stains on clothes and the removal of rust.
[22] Bleaching action of chlorine is by -
A.
decomposition
B.
hydrolysis
C.
reduction
D.
oxidation
Ans:
oxidation
Explanation :
Chlorine bleaches by the process of oxidation. It needs moisture for its bleaching action. Chlorine reacts with water to form hydrochloric and hypochlorous acids.
[23] Hardest material is -
A.
Tungsten
B.
Diamond
C.
Steel
D.
Graphite
Ans:
Diamond
Explanation :
Diamondsare commonly known as the hardest substance on earth, used in drill bits for cutting applications. Diamond is currently thought to be the hardest natural material on Earth, having a hardness of ten out of ten on the Mohs scale of mineral hardness. Diamond is made up of carbon atoms which share strong covalent bonds (where electrons are shared between atoms) and are equally spaced in a lattice arrangement.
[24] When iron rusts, its weight -
A.
decreases
B.
increases
C.
Constant
D.
None
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[25] Which of the following is not a donor atom?
A.
Phosphorus
B.
Antimony
C.
Arsenic
D.
Aluminium
Ans:
Aluminium
Explanation :
Aluminium is an acceptor atom, an impurity atom in a semiconductor, which can accept or take up one or more electrons from the crystal and become negatively charged.
Explanation :
Methyl bromide- is considered to be a significant ozone depleting substance (ODS) by atmospheric scientists. While methyl bromide is a natural substance, the additional methyl bromide added to the atmosphere by humans contributes to the thinning of the ozone layer, allowing increased UV radiation to reach the earth's surface, with potential impact not only to human health and the environment, but to agricultural crops as well.
[8] Galvanised iron is made by coating iron with –
A.
Zinc
B.
Nickel
C.
Chromium
D.
Sulphur
Ans:
Zinc
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.
[9] An atomic pile is used for –
A.
producing X-rays
B.
conducting nuclear fission
C.
conducting thermonuclear fusion
D.
accelerating atoms
Ans:
conducting nuclear fission
Explanation :
An atomic pile is a nuclear reactor that uses controlled nuclear fission to generate energy. The most common reactor consists of a large assembly of graphite (an allotropic form of carbon) blocks having rods of uranium metal (fuel).
[10] Which of the following type of coal has the lowest proportion of volatile matter?
A.
Lignite
B.
Peat
C.
Bituminous
D.
Anthracite
Ans:
Anthracite
Explanation :
Anthracite has the lowest proportion of volatile matter. Volatile matter in coal refers to the components of coal, except for moisture, which are liberated at high temperature in the absence of air. This is usually a mixture of short and long chain hydrocarbons, aromatic hydrocarbons and some sulfur. The volatile matter of coal is determined under rigidly controlled standards.
[11] The compound to which H2 does not add is –
A.
Biphenyl ethylene
B.
Tetraphenyl ethylene
C.
Tetra - a - naphthylethylene
D.
Tetra - 9 - phenanthrylethylene
Ans:
Tetraphenyl ethylene
Explanation :
While H2 is not very reactive under standard conditions, it does form compounds with most elements. Millions of hydrocarbons are known, but they are not formed by the direct reaction of elementary hydrogen and carbon. Hydrogen can form compounds with elements that are more electronegative, such as halogens. Hydrogen forms a vast array of compounds with carbon.
[12] Major gaseous pollutant of the thermal power station is –
A.
H2S
B.
NH3
C.
NO2
D.
SO2
Ans:
SO2
Explanation :
A flue-gas stack is a type of chimney, a vertical pipe, channel or similar structure through which combustion product gases called flue gases are exhausted to the outside air. Flue gases are produced when coal, oil, natural gas, wood or any other fuel is combusted in an industrial furnace, a power plant's steam-generating boiler, or other large combustion device. Flue was is usually composed of carbon dioxide (CO2) and water vapor as well as nitrogen and excess oxygen remaining from the intake combustion air.
[13] The process of removing calcium and magnesium from hard water is known as –
A.
Sedimentation
B.
Filtration
C.
Flocculation
D.
Water softening
Ans:
Water softening
Explanation :
Water softening is the reduction of the concentration of calcium, magnesium, and certain other metal cations in hard water. Hardness ions dissolved in water can cause a variety of undesired effects including interfering with the action of soaps, the buildup of limescale, which can foul plumbing, and galvanic corrosion. Conventional water-softening appliances intended for household use depend on an ion-exchange resin in which hardness ions are exchanged for sodium ions. Water softening may be desirable where the source of water is hard. However, hard water also conveys some benefits to health by reducing the solubility of potentially toxic metal ions such as lead and copper.
[14] Which of the following metals causes Itai-Itai disease?
A.
Cadmium
B.
Chromium
C.
Cobalt
D.
Copper
Ans:
Cadmium
Explanation :
Itai-itai disease was the documented case of mass cadmium poisoning in Toyama Prefecture, Japan, starting around 1912. The cadmium poisoning caused softening of the bones and kidney failure. The disease is named for the severe pains caused in the joints and spine. The cadmium was released into rivers by mining companies in the mountains. The mining companies were successfully sued for the damage. Itai-itai disease is known as one of the Four Big Pollution Diseases of Japan.
[15] Which is used in preparation of dynamite?
A.
glycerol
B.
ethyl alcohol
C.
methyl alcohol
D.
glycol
Ans:
glycerol
Explanation :
Dynamite is an explosive made of nitroglycerin, sorbents (such as powdered shells or clay) and stabilizers. It was invented by the Swedish chemist and engineer Alfred Nobel in Geesthacht, and patented in 1867.
[16] Vinegar is the trade name of -
A.
acetic acid
B.
chloroform
C.
carbon tetrachloride
D.
ethyl alcohol
Ans:
acetic acid
Explanation :
The trivial name acetic acid is the most commonly used and preferred IUPAC name. The systematic name ethanoic acid, a valid IUPAC name, is constructed according to the substitutive nomenclature.
[17] Acid secretion is characteristic of -
A.
Buccal cavity
B.
Stomach
C.
Small intestine
D.
Large intestine
Ans:
Stomach
Explanation :
The stomach is famous for its secretion of hydrochloric acid. It is secreted from parietal cells into the lumen where it establishes an extremely acidic environment. This acid is important for activation of pepsinogen and inactivation of ingested microorganisms such as bacteria.
[18] Which one of the following is not a fertilizer?
A.
Ammonium sulphate
B.
Calcium sulphate
C.
Calcium ammonium nitrate
D.
Potassium nitrate
Ans:
Calcium sulphate
Explanation :
Calcium sulfate is a common laboratory and industrial chemical. In the form of -anhydrite (the nearly anhydrous form), it is used as a desiccant. It is also used as a coagulant in products like tofu. The main sources of calcium sulfate are naturally occurring gypsum and anhydrite which occur at many locations worldwide as evaporites.
[19] The common refrigerant in domestic refrigerator is -
A.
Neon
B.
Oxygen
C.
Nitrogen
D.
Freon
Ans:
Freon
Explanation :
Common refrigerants used in domestic refrigerators are freon, neon and nitrogen. It flows through four components of refrigerator again and again. These four components are cooling chamber, compressor, heat exchanger and expander
[20] The chemical name of “laughing gas” is -
A.
Nitric oxide
B.
Nitrogen dioxide
C.
Nitrogen pentoxide
D.
Nitrous oxide
Ans:
Nitrous oxide
Explanation :
Nitrous oxide, commonly known as laughing gas, is a chemical compound with the formula N2O. It is used in surgery and dentistry for its anesthetic and analgesic effects. It is known as "laughing gas" due to the euphoric effects of inhaling it, a property that has led to its recreational use as a dissociative anesthetic.
[21] Which of the following is used to remove ink and rust stains on cloth?
A.
Oxalic acid
B.
Alcohol
C.
Ether
D.
Kerosene oil
Ans:
Oxalic acid
Explanation :
Oxalic acid is a reducing agent and its conjugate base, known as oxalate, is a chelating agent for metal cations and stain removal. Oxalic acid's main applications include cleaning or bleaching, removal of stains on clothes and the removal of rust.
[22] Bleaching action of chlorine is by -
A.
decomposition
B.
hydrolysis
C.
reduction
D.
oxidation
Ans:
oxidation
Explanation :
Chlorine bleaches by the process of oxidation. It needs moisture for its bleaching action. Chlorine reacts with water to form hydrochloric and hypochlorous acids.
[23] Hardest material is -
A.
Tungsten
B.
Diamond
C.
Steel
D.
Graphite
Ans:
Diamond
Explanation :
Diamondsare commonly known as the hardest substance on earth, used in drill bits for cutting applications. Diamond is currently thought to be the hardest natural material on Earth, having a hardness of ten out of ten on the Mohs scale of mineral hardness. Diamond is made up of carbon atoms which share strong covalent bonds (where electrons are shared between atoms) and are equally spaced in a lattice arrangement.
[24] When iron rusts, its weight -
A.
decreases
B.
increases
C.
Constant
D.
None
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[25] Which of the following is not a donor atom?
A.
Phosphorus
B.
Antimony
C.
Arsenic
D.
Aluminium
Ans:
Aluminium
Explanation :
Aluminium is an acceptor atom, an impurity atom in a semiconductor, which can accept or take up one or more electrons from the crystal and become negatively charged.
Explanation :
An atomic pile is a nuclear reactor that uses controlled nuclear fission to generate energy. The most common reactor consists of a large assembly of graphite (an allotropic form of carbon) blocks having rods of uranium metal (fuel).
[10] Which of the following type of coal has the lowest proportion of volatile matter?
A.
Lignite
B.
Peat
C.
Bituminous
D.
Anthracite
Ans:
Anthracite
Explanation :
Anthracite has the lowest proportion of volatile matter. Volatile matter in coal refers to the components of coal, except for moisture, which are liberated at high temperature in the absence of air. This is usually a mixture of short and long chain hydrocarbons, aromatic hydrocarbons and some sulfur. The volatile matter of coal is determined under rigidly controlled standards.
[11] The compound to which H2 does not add is –
A.
Biphenyl ethylene
B.
Tetraphenyl ethylene
C.
Tetra - a - naphthylethylene
D.
Tetra - 9 - phenanthrylethylene
Ans:
Tetraphenyl ethylene
Explanation :
While H2 is not very reactive under standard conditions, it does form compounds with most elements. Millions of hydrocarbons are known, but they are not formed by the direct reaction of elementary hydrogen and carbon. Hydrogen can form compounds with elements that are more electronegative, such as halogens. Hydrogen forms a vast array of compounds with carbon.
[12] Major gaseous pollutant of the thermal power station is –
A.
H2S
B.
NH3
C.
NO2
D.
SO2
Ans:
SO2
Explanation :
A flue-gas stack is a type of chimney, a vertical pipe, channel or similar structure through which combustion product gases called flue gases are exhausted to the outside air. Flue gases are produced when coal, oil, natural gas, wood or any other fuel is combusted in an industrial furnace, a power plant's steam-generating boiler, or other large combustion device. Flue was is usually composed of carbon dioxide (CO2) and water vapor as well as nitrogen and excess oxygen remaining from the intake combustion air.
[13] The process of removing calcium and magnesium from hard water is known as –
A.
Sedimentation
B.
Filtration
C.
Flocculation
D.
Water softening
Ans:
Water softening
Explanation :
Water softening is the reduction of the concentration of calcium, magnesium, and certain other metal cations in hard water. Hardness ions dissolved in water can cause a variety of undesired effects including interfering with the action of soaps, the buildup of limescale, which can foul plumbing, and galvanic corrosion. Conventional water-softening appliances intended for household use depend on an ion-exchange resin in which hardness ions are exchanged for sodium ions. Water softening may be desirable where the source of water is hard. However, hard water also conveys some benefits to health by reducing the solubility of potentially toxic metal ions such as lead and copper.
[14] Which of the following metals causes Itai-Itai disease?
A.
Cadmium
B.
Chromium
C.
Cobalt
D.
Copper
Ans:
Cadmium
Explanation :
Itai-itai disease was the documented case of mass cadmium poisoning in Toyama Prefecture, Japan, starting around 1912. The cadmium poisoning caused softening of the bones and kidney failure. The disease is named for the severe pains caused in the joints and spine. The cadmium was released into rivers by mining companies in the mountains. The mining companies were successfully sued for the damage. Itai-itai disease is known as one of the Four Big Pollution Diseases of Japan.
[15] Which is used in preparation of dynamite?
A.
glycerol
B.
ethyl alcohol
C.
methyl alcohol
D.
glycol
Ans:
glycerol
Explanation :
Dynamite is an explosive made of nitroglycerin, sorbents (such as powdered shells or clay) and stabilizers. It was invented by the Swedish chemist and engineer Alfred Nobel in Geesthacht, and patented in 1867.
[16] Vinegar is the trade name of -
A.
acetic acid
B.
chloroform
C.
carbon tetrachloride
D.
ethyl alcohol
Ans:
acetic acid
Explanation :
The trivial name acetic acid is the most commonly used and preferred IUPAC name. The systematic name ethanoic acid, a valid IUPAC name, is constructed according to the substitutive nomenclature.
[17] Acid secretion is characteristic of -
A.
Buccal cavity
B.
Stomach
C.
Small intestine
D.
Large intestine
Ans:
Stomach
Explanation :
The stomach is famous for its secretion of hydrochloric acid. It is secreted from parietal cells into the lumen where it establishes an extremely acidic environment. This acid is important for activation of pepsinogen and inactivation of ingested microorganisms such as bacteria.
[18] Which one of the following is not a fertilizer?
A.
Ammonium sulphate
B.
Calcium sulphate
C.
Calcium ammonium nitrate
D.
Potassium nitrate
Ans:
Calcium sulphate
Explanation :
Calcium sulfate is a common laboratory and industrial chemical. In the form of -anhydrite (the nearly anhydrous form), it is used as a desiccant. It is also used as a coagulant in products like tofu. The main sources of calcium sulfate are naturally occurring gypsum and anhydrite which occur at many locations worldwide as evaporites.
[19] The common refrigerant in domestic refrigerator is -
A.
Neon
B.
Oxygen
C.
Nitrogen
D.
Freon
Ans:
Freon
Explanation :
Common refrigerants used in domestic refrigerators are freon, neon and nitrogen. It flows through four components of refrigerator again and again. These four components are cooling chamber, compressor, heat exchanger and expander
[20] The chemical name of “laughing gas” is -
A.
Nitric oxide
B.
Nitrogen dioxide
C.
Nitrogen pentoxide
D.
Nitrous oxide
Ans:
Nitrous oxide
Explanation :
Nitrous oxide, commonly known as laughing gas, is a chemical compound with the formula N2O. It is used in surgery and dentistry for its anesthetic and analgesic effects. It is known as "laughing gas" due to the euphoric effects of inhaling it, a property that has led to its recreational use as a dissociative anesthetic.
[21] Which of the following is used to remove ink and rust stains on cloth?
A.
Oxalic acid
B.
Alcohol
C.
Ether
D.
Kerosene oil
Ans:
Oxalic acid
Explanation :
Oxalic acid is a reducing agent and its conjugate base, known as oxalate, is a chelating agent for metal cations and stain removal. Oxalic acid's main applications include cleaning or bleaching, removal of stains on clothes and the removal of rust.
[22] Bleaching action of chlorine is by -
A.
decomposition
B.
hydrolysis
C.
reduction
D.
oxidation
Ans:
oxidation
Explanation :
Chlorine bleaches by the process of oxidation. It needs moisture for its bleaching action. Chlorine reacts with water to form hydrochloric and hypochlorous acids.
[23] Hardest material is -
A.
Tungsten
B.
Diamond
C.
Steel
D.
Graphite
Ans:
Diamond
Explanation :
Diamondsare commonly known as the hardest substance on earth, used in drill bits for cutting applications. Diamond is currently thought to be the hardest natural material on Earth, having a hardness of ten out of ten on the Mohs scale of mineral hardness. Diamond is made up of carbon atoms which share strong covalent bonds (where electrons are shared between atoms) and are equally spaced in a lattice arrangement.
[24] When iron rusts, its weight -
A.
decreases
B.
increases
C.
Constant
D.
None
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[25] Which of the following is not a donor atom?
A.
Phosphorus
B.
Antimony
C.
Arsenic
D.
Aluminium
Ans:
Aluminium
Explanation :
Aluminium is an acceptor atom, an impurity atom in a semiconductor, which can accept or take up one or more electrons from the crystal and become negatively charged.
Explanation :
While H2 is not very reactive under standard conditions, it does form compounds with most elements. Millions of hydrocarbons are known, but they are not formed by the direct reaction of elementary hydrogen and carbon. Hydrogen can form compounds with elements that are more electronegative, such as halogens. Hydrogen forms a vast array of compounds with carbon.
[12] Major gaseous pollutant of the thermal power station is –
A.
H2S
B.
NH3
C.
NO2
D.
SO2
Ans:
SO2
Explanation :
A flue-gas stack is a type of chimney, a vertical pipe, channel or similar structure through which combustion product gases called flue gases are exhausted to the outside air. Flue gases are produced when coal, oil, natural gas, wood or any other fuel is combusted in an industrial furnace, a power plant's steam-generating boiler, or other large combustion device. Flue was is usually composed of carbon dioxide (CO2) and water vapor as well as nitrogen and excess oxygen remaining from the intake combustion air.
[13] The process of removing calcium and magnesium from hard water is known as –
A.
Sedimentation
B.
Filtration
C.
Flocculation
D.
Water softening
Ans:
Water softening
Explanation :
Water softening is the reduction of the concentration of calcium, magnesium, and certain other metal cations in hard water. Hardness ions dissolved in water can cause a variety of undesired effects including interfering with the action of soaps, the buildup of limescale, which can foul plumbing, and galvanic corrosion. Conventional water-softening appliances intended for household use depend on an ion-exchange resin in which hardness ions are exchanged for sodium ions. Water softening may be desirable where the source of water is hard. However, hard water also conveys some benefits to health by reducing the solubility of potentially toxic metal ions such as lead and copper.
[14] Which of the following metals causes Itai-Itai disease?
A.
Cadmium
B.
Chromium
C.
Cobalt
D.
Copper
Ans:
Cadmium
Explanation :
Itai-itai disease was the documented case of mass cadmium poisoning in Toyama Prefecture, Japan, starting around 1912. The cadmium poisoning caused softening of the bones and kidney failure. The disease is named for the severe pains caused in the joints and spine. The cadmium was released into rivers by mining companies in the mountains. The mining companies were successfully sued for the damage. Itai-itai disease is known as one of the Four Big Pollution Diseases of Japan.
[15] Which is used in preparation of dynamite?
A.
glycerol
B.
ethyl alcohol
C.
methyl alcohol
D.
glycol
Ans:
glycerol
Explanation :
Dynamite is an explosive made of nitroglycerin, sorbents (such as powdered shells or clay) and stabilizers. It was invented by the Swedish chemist and engineer Alfred Nobel in Geesthacht, and patented in 1867.
[16] Vinegar is the trade name of -
A.
acetic acid
B.
chloroform
C.
carbon tetrachloride
D.
ethyl alcohol
Ans:
acetic acid
Explanation :
The trivial name acetic acid is the most commonly used and preferred IUPAC name. The systematic name ethanoic acid, a valid IUPAC name, is constructed according to the substitutive nomenclature.
[17] Acid secretion is characteristic of -
A.
Buccal cavity
B.
Stomach
C.
Small intestine
D.
Large intestine
Ans:
Stomach
Explanation :
The stomach is famous for its secretion of hydrochloric acid. It is secreted from parietal cells into the lumen where it establishes an extremely acidic environment. This acid is important for activation of pepsinogen and inactivation of ingested microorganisms such as bacteria.
[18] Which one of the following is not a fertilizer?
A.
Ammonium sulphate
B.
Calcium sulphate
C.
Calcium ammonium nitrate
D.
Potassium nitrate
Ans:
Calcium sulphate
Explanation :
Calcium sulfate is a common laboratory and industrial chemical. In the form of -anhydrite (the nearly anhydrous form), it is used as a desiccant. It is also used as a coagulant in products like tofu. The main sources of calcium sulfate are naturally occurring gypsum and anhydrite which occur at many locations worldwide as evaporites.
[19] The common refrigerant in domestic refrigerator is -
A.
Neon
B.
Oxygen
C.
Nitrogen
D.
Freon
Ans:
Freon
Explanation :
Common refrigerants used in domestic refrigerators are freon, neon and nitrogen. It flows through four components of refrigerator again and again. These four components are cooling chamber, compressor, heat exchanger and expander
[20] The chemical name of “laughing gas” is -
A.
Nitric oxide
B.
Nitrogen dioxide
C.
Nitrogen pentoxide
D.
Nitrous oxide
Ans:
Nitrous oxide
Explanation :
Nitrous oxide, commonly known as laughing gas, is a chemical compound with the formula N2O. It is used in surgery and dentistry for its anesthetic and analgesic effects. It is known as "laughing gas" due to the euphoric effects of inhaling it, a property that has led to its recreational use as a dissociative anesthetic.
[21] Which of the following is used to remove ink and rust stains on cloth?
A.
Oxalic acid
B.
Alcohol
C.
Ether
D.
Kerosene oil
Ans:
Oxalic acid
Explanation :
Oxalic acid is a reducing agent and its conjugate base, known as oxalate, is a chelating agent for metal cations and stain removal. Oxalic acid's main applications include cleaning or bleaching, removal of stains on clothes and the removal of rust.
[22] Bleaching action of chlorine is by -
A.
decomposition
B.
hydrolysis
C.
reduction
D.
oxidation
Ans:
oxidation
Explanation :
Chlorine bleaches by the process of oxidation. It needs moisture for its bleaching action. Chlorine reacts with water to form hydrochloric and hypochlorous acids.
[23] Hardest material is -
A.
Tungsten
B.
Diamond
C.
Steel
D.
Graphite
Ans:
Diamond
Explanation :
Diamondsare commonly known as the hardest substance on earth, used in drill bits for cutting applications. Diamond is currently thought to be the hardest natural material on Earth, having a hardness of ten out of ten on the Mohs scale of mineral hardness. Diamond is made up of carbon atoms which share strong covalent bonds (where electrons are shared between atoms) and are equally spaced in a lattice arrangement.
[24] When iron rusts, its weight -
A.
decreases
B.
increases
C.
Constant
D.
None
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[25] Which of the following is not a donor atom?
A.
Phosphorus
B.
Antimony
C.
Arsenic
D.
Aluminium
Ans:
Aluminium
Explanation :
Aluminium is an acceptor atom, an impurity atom in a semiconductor, which can accept or take up one or more electrons from the crystal and become negatively charged.
Explanation :
Water softening is the reduction of the concentration of calcium, magnesium, and certain other metal cations in hard water. Hardness ions dissolved in water can cause a variety of undesired effects including interfering with the action of soaps, the buildup of limescale, which can foul plumbing, and galvanic corrosion. Conventional water-softening appliances intended for household use depend on an ion-exchange resin in which hardness ions are exchanged for sodium ions. Water softening may be desirable where the source of water is hard. However, hard water also conveys some benefits to health by reducing the solubility of potentially toxic metal ions such as lead and copper.
[14] Which of the following metals causes Itai-Itai disease?
A.
Cadmium
B.
Chromium
C.
Cobalt
D.
Copper
Ans:
Cadmium
Explanation :
Itai-itai disease was the documented case of mass cadmium poisoning in Toyama Prefecture, Japan, starting around 1912. The cadmium poisoning caused softening of the bones and kidney failure. The disease is named for the severe pains caused in the joints and spine. The cadmium was released into rivers by mining companies in the mountains. The mining companies were successfully sued for the damage. Itai-itai disease is known as one of the Four Big Pollution Diseases of Japan.
[15] Which is used in preparation of dynamite?
A.
glycerol
B.
ethyl alcohol
C.
methyl alcohol
D.
glycol
Ans:
glycerol
Explanation :
Dynamite is an explosive made of nitroglycerin, sorbents (such as powdered shells or clay) and stabilizers. It was invented by the Swedish chemist and engineer Alfred Nobel in Geesthacht, and patented in 1867.
[16] Vinegar is the trade name of -
A.
acetic acid
B.
chloroform
C.
carbon tetrachloride
D.
ethyl alcohol
Ans:
acetic acid
Explanation :
The trivial name acetic acid is the most commonly used and preferred IUPAC name. The systematic name ethanoic acid, a valid IUPAC name, is constructed according to the substitutive nomenclature.
[17] Acid secretion is characteristic of -
A.
Buccal cavity
B.
Stomach
C.
Small intestine
D.
Large intestine
Ans:
Stomach
Explanation :
The stomach is famous for its secretion of hydrochloric acid. It is secreted from parietal cells into the lumen where it establishes an extremely acidic environment. This acid is important for activation of pepsinogen and inactivation of ingested microorganisms such as bacteria.
[18] Which one of the following is not a fertilizer?
A.
Ammonium sulphate
B.
Calcium sulphate
C.
Calcium ammonium nitrate
D.
Potassium nitrate
Ans:
Calcium sulphate
Explanation :
Calcium sulfate is a common laboratory and industrial chemical. In the form of -anhydrite (the nearly anhydrous form), it is used as a desiccant. It is also used as a coagulant in products like tofu. The main sources of calcium sulfate are naturally occurring gypsum and anhydrite which occur at many locations worldwide as evaporites.
[19] The common refrigerant in domestic refrigerator is -
A.
Neon
B.
Oxygen
C.
Nitrogen
D.
Freon
Ans:
Freon
Explanation :
Common refrigerants used in domestic refrigerators are freon, neon and nitrogen. It flows through four components of refrigerator again and again. These four components are cooling chamber, compressor, heat exchanger and expander
[20] The chemical name of “laughing gas” is -
A.
Nitric oxide
B.
Nitrogen dioxide
C.
Nitrogen pentoxide
D.
Nitrous oxide
Ans:
Nitrous oxide
Explanation :
Nitrous oxide, commonly known as laughing gas, is a chemical compound with the formula N2O. It is used in surgery and dentistry for its anesthetic and analgesic effects. It is known as "laughing gas" due to the euphoric effects of inhaling it, a property that has led to its recreational use as a dissociative anesthetic.
[21] Which of the following is used to remove ink and rust stains on cloth?
A.
Oxalic acid
B.
Alcohol
C.
Ether
D.
Kerosene oil
Ans:
Oxalic acid
Explanation :
Oxalic acid is a reducing agent and its conjugate base, known as oxalate, is a chelating agent for metal cations and stain removal. Oxalic acid's main applications include cleaning or bleaching, removal of stains on clothes and the removal of rust.
[22] Bleaching action of chlorine is by -
A.
decomposition
B.
hydrolysis
C.
reduction
D.
oxidation
Ans:
oxidation
Explanation :
Chlorine bleaches by the process of oxidation. It needs moisture for its bleaching action. Chlorine reacts with water to form hydrochloric and hypochlorous acids.
[23] Hardest material is -
A.
Tungsten
B.
Diamond
C.
Steel
D.
Graphite
Ans:
Diamond
Explanation :
Diamondsare commonly known as the hardest substance on earth, used in drill bits for cutting applications. Diamond is currently thought to be the hardest natural material on Earth, having a hardness of ten out of ten on the Mohs scale of mineral hardness. Diamond is made up of carbon atoms which share strong covalent bonds (where electrons are shared between atoms) and are equally spaced in a lattice arrangement.
[24] When iron rusts, its weight -
A.
decreases
B.
increases
C.
Constant
D.
None
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[25] Which of the following is not a donor atom?
A.
Phosphorus
B.
Antimony
C.
Arsenic
D.
Aluminium
Ans:
Aluminium
Explanation :
Aluminium is an acceptor atom, an impurity atom in a semiconductor, which can accept or take up one or more electrons from the crystal and become negatively charged.
Explanation :
Dynamite is an explosive made of nitroglycerin, sorbents (such as powdered shells or clay) and stabilizers. It was invented by the Swedish chemist and engineer Alfred Nobel in Geesthacht, and patented in 1867.
[16] Vinegar is the trade name of -
A.
acetic acid
B.
chloroform
C.
carbon tetrachloride
D.
ethyl alcohol
Ans:
acetic acid
Explanation :
The trivial name acetic acid is the most commonly used and preferred IUPAC name. The systematic name ethanoic acid, a valid IUPAC name, is constructed according to the substitutive nomenclature.
[17] Acid secretion is characteristic of -
A.
Buccal cavity
B.
Stomach
C.
Small intestine
D.
Large intestine
Ans:
Stomach
Explanation :
The stomach is famous for its secretion of hydrochloric acid. It is secreted from parietal cells into the lumen where it establishes an extremely acidic environment. This acid is important for activation of pepsinogen and inactivation of ingested microorganisms such as bacteria.
[18] Which one of the following is not a fertilizer?
A.
Ammonium sulphate
B.
Calcium sulphate
C.
Calcium ammonium nitrate
D.
Potassium nitrate
Ans:
Calcium sulphate
Explanation :
Calcium sulfate is a common laboratory and industrial chemical. In the form of -anhydrite (the nearly anhydrous form), it is used as a desiccant. It is also used as a coagulant in products like tofu. The main sources of calcium sulfate are naturally occurring gypsum and anhydrite which occur at many locations worldwide as evaporites.
[19] The common refrigerant in domestic refrigerator is -
A.
Neon
B.
Oxygen
C.
Nitrogen
D.
Freon
Ans:
Freon
Explanation :
Common refrigerants used in domestic refrigerators are freon, neon and nitrogen. It flows through four components of refrigerator again and again. These four components are cooling chamber, compressor, heat exchanger and expander
[20] The chemical name of “laughing gas” is -
A.
Nitric oxide
B.
Nitrogen dioxide
C.
Nitrogen pentoxide
D.
Nitrous oxide
Ans:
Nitrous oxide
Explanation :
Nitrous oxide, commonly known as laughing gas, is a chemical compound with the formula N2O. It is used in surgery and dentistry for its anesthetic and analgesic effects. It is known as "laughing gas" due to the euphoric effects of inhaling it, a property that has led to its recreational use as a dissociative anesthetic.
[21] Which of the following is used to remove ink and rust stains on cloth?
A.
Oxalic acid
B.
Alcohol
C.
Ether
D.
Kerosene oil
Ans:
Oxalic acid
Explanation :
Oxalic acid is a reducing agent and its conjugate base, known as oxalate, is a chelating agent for metal cations and stain removal. Oxalic acid's main applications include cleaning or bleaching, removal of stains on clothes and the removal of rust.
[22] Bleaching action of chlorine is by -
A.
decomposition
B.
hydrolysis
C.
reduction
D.
oxidation
Ans:
oxidation
Explanation :
Chlorine bleaches by the process of oxidation. It needs moisture for its bleaching action. Chlorine reacts with water to form hydrochloric and hypochlorous acids.
[23] Hardest material is -
A.
Tungsten
B.
Diamond
C.
Steel
D.
Graphite
Ans:
Diamond
Explanation :
Diamondsare commonly known as the hardest substance on earth, used in drill bits for cutting applications. Diamond is currently thought to be the hardest natural material on Earth, having a hardness of ten out of ten on the Mohs scale of mineral hardness. Diamond is made up of carbon atoms which share strong covalent bonds (where electrons are shared between atoms) and are equally spaced in a lattice arrangement.
[24] When iron rusts, its weight -
A.
decreases
B.
increases
C.
Constant
D.
None
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[25] Which of the following is not a donor atom?
A.
Phosphorus
B.
Antimony
C.
Arsenic
D.
Aluminium
Ans:
Aluminium
Explanation :
Aluminium is an acceptor atom, an impurity atom in a semiconductor, which can accept or take up one or more electrons from the crystal and become negatively charged.
Explanation :
The stomach is famous for its secretion of hydrochloric acid. It is secreted from parietal cells into the lumen where it establishes an extremely acidic environment. This acid is important for activation of pepsinogen and inactivation of ingested microorganisms such as bacteria.
[18] Which one of the following is not a fertilizer?
A.
Ammonium sulphate
B.
Calcium sulphate
C.
Calcium ammonium nitrate
D.
Potassium nitrate
Ans:
Calcium sulphate
Explanation :
Calcium sulfate is a common laboratory and industrial chemical. In the form of -anhydrite (the nearly anhydrous form), it is used as a desiccant. It is also used as a coagulant in products like tofu. The main sources of calcium sulfate are naturally occurring gypsum and anhydrite which occur at many locations worldwide as evaporites.
[19] The common refrigerant in domestic refrigerator is -
A.
Neon
B.
Oxygen
C.
Nitrogen
D.
Freon
Ans:
Freon
Explanation :
Common refrigerants used in domestic refrigerators are freon, neon and nitrogen. It flows through four components of refrigerator again and again. These four components are cooling chamber, compressor, heat exchanger and expander
[20] The chemical name of “laughing gas” is -
A.
Nitric oxide
B.
Nitrogen dioxide
C.
Nitrogen pentoxide
D.
Nitrous oxide
Ans:
Nitrous oxide
Explanation :
Nitrous oxide, commonly known as laughing gas, is a chemical compound with the formula N2O. It is used in surgery and dentistry for its anesthetic and analgesic effects. It is known as "laughing gas" due to the euphoric effects of inhaling it, a property that has led to its recreational use as a dissociative anesthetic.
[21] Which of the following is used to remove ink and rust stains on cloth?
A.
Oxalic acid
B.
Alcohol
C.
Ether
D.
Kerosene oil
Ans:
Oxalic acid
Explanation :
Oxalic acid is a reducing agent and its conjugate base, known as oxalate, is a chelating agent for metal cations and stain removal. Oxalic acid's main applications include cleaning or bleaching, removal of stains on clothes and the removal of rust.
[22] Bleaching action of chlorine is by -
A.
decomposition
B.
hydrolysis
C.
reduction
D.
oxidation
Ans:
oxidation
Explanation :
Chlorine bleaches by the process of oxidation. It needs moisture for its bleaching action. Chlorine reacts with water to form hydrochloric and hypochlorous acids.
[23] Hardest material is -
A.
Tungsten
B.
Diamond
C.
Steel
D.
Graphite
Ans:
Diamond
Explanation :
Diamondsare commonly known as the hardest substance on earth, used in drill bits for cutting applications. Diamond is currently thought to be the hardest natural material on Earth, having a hardness of ten out of ten on the Mohs scale of mineral hardness. Diamond is made up of carbon atoms which share strong covalent bonds (where electrons are shared between atoms) and are equally spaced in a lattice arrangement.
[24] When iron rusts, its weight -
A.
decreases
B.
increases
C.
Constant
D.
None
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[25] Which of the following is not a donor atom?
A.
Phosphorus
B.
Antimony
C.
Arsenic
D.
Aluminium
Ans:
Aluminium
Explanation :
Aluminium is an acceptor atom, an impurity atom in a semiconductor, which can accept or take up one or more electrons from the crystal and become negatively charged.
Explanation :
Common refrigerants used in domestic refrigerators are freon, neon and nitrogen. It flows through four components of refrigerator again and again. These four components are cooling chamber, compressor, heat exchanger and expander
[20] The chemical name of “laughing gas” is -
A.
Nitric oxide
B.
Nitrogen dioxide
C.
Nitrogen pentoxide
D.
Nitrous oxide
Ans:
Nitrous oxide
Explanation :
Nitrous oxide, commonly known as laughing gas, is a chemical compound with the formula N2O. It is used in surgery and dentistry for its anesthetic and analgesic effects. It is known as "laughing gas" due to the euphoric effects of inhaling it, a property that has led to its recreational use as a dissociative anesthetic.
[21] Which of the following is used to remove ink and rust stains on cloth?
A.
Oxalic acid
B.
Alcohol
C.
Ether
D.
Kerosene oil
Ans:
Oxalic acid
Explanation :
Oxalic acid is a reducing agent and its conjugate base, known as oxalate, is a chelating agent for metal cations and stain removal. Oxalic acid's main applications include cleaning or bleaching, removal of stains on clothes and the removal of rust.
[22] Bleaching action of chlorine is by -
A.
decomposition
B.
hydrolysis
C.
reduction
D.
oxidation
Ans:
oxidation
Explanation :
Chlorine bleaches by the process of oxidation. It needs moisture for its bleaching action. Chlorine reacts with water to form hydrochloric and hypochlorous acids.
[23] Hardest material is -
A.
Tungsten
B.
Diamond
C.
Steel
D.
Graphite
Ans:
Diamond
Explanation :
Diamondsare commonly known as the hardest substance on earth, used in drill bits for cutting applications. Diamond is currently thought to be the hardest natural material on Earth, having a hardness of ten out of ten on the Mohs scale of mineral hardness. Diamond is made up of carbon atoms which share strong covalent bonds (where electrons are shared between atoms) and are equally spaced in a lattice arrangement.
[24] When iron rusts, its weight -
A.
decreases
B.
increases
C.
Constant
D.
None
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[25] Which of the following is not a donor atom?
A.
Phosphorus
B.
Antimony
C.
Arsenic
D.
Aluminium
Ans:
Aluminium
Explanation :
Aluminium is an acceptor atom, an impurity atom in a semiconductor, which can accept or take up one or more electrons from the crystal and become negatively charged.
Explanation :
Oxalic acid is a reducing agent and its conjugate base, known as oxalate, is a chelating agent for metal cations and stain removal. Oxalic acid's main applications include cleaning or bleaching, removal of stains on clothes and the removal of rust.
[22] Bleaching action of chlorine is by -
A.
decomposition
B.
hydrolysis
C.
reduction
D.
oxidation
Ans:
oxidation
Explanation :
Chlorine bleaches by the process of oxidation. It needs moisture for its bleaching action. Chlorine reacts with water to form hydrochloric and hypochlorous acids.
[23] Hardest material is -
A.
Tungsten
B.
Diamond
C.
Steel
D.
Graphite
Ans:
Diamond
Explanation :
Diamondsare commonly known as the hardest substance on earth, used in drill bits for cutting applications. Diamond is currently thought to be the hardest natural material on Earth, having a hardness of ten out of ten on the Mohs scale of mineral hardness. Diamond is made up of carbon atoms which share strong covalent bonds (where electrons are shared between atoms) and are equally spaced in a lattice arrangement.
[24] When iron rusts, its weight -
A.
decreases
B.
increases
C.
Constant
D.
None
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[25] Which of the following is not a donor atom?
A.
Phosphorus
B.
Antimony
C.
Arsenic
D.
Aluminium
Ans:
Aluminium
Explanation :
Aluminium is an acceptor atom, an impurity atom in a semiconductor, which can accept or take up one or more electrons from the crystal and become negatively charged.
Explanation :
Diamondsare commonly known as the hardest substance on earth, used in drill bits for cutting applications. Diamond is currently thought to be the hardest natural material on Earth, having a hardness of ten out of ten on the Mohs scale of mineral hardness. Diamond is made up of carbon atoms which share strong covalent bonds (where electrons are shared between atoms) and are equally spaced in a lattice arrangement.
[24] When iron rusts, its weight -
A.
decreases
B.
increases
C.
Constant
D.
None
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[25] Which of the following is not a donor atom?
A.
Phosphorus
B.
Antimony
C.
Arsenic
D.
Aluminium
Ans:
Aluminium
Explanation :
Aluminium is an acceptor atom, an impurity atom in a semiconductor, which can accept or take up one or more electrons from the crystal and become negatively charged.
Explanation :
Aluminium is an acceptor atom, an impurity atom in a semiconductor, which can accept or take up one or more electrons from the crystal and become negatively charged.