[1] When ice cubes are made, the entropy of water –
A.
does not change
B.
decreases
C.
increases
D.
may either increase or decrease depending on the process used
Ans:
decreases
Explanation :
When water is frozen into ice, the temperature drops below 0°C. Since the entropy of the solid is less than that of the liquid, the entropy of the water (the system here) will decrease on freezing. The amount of decrease is found by dividing the heat of fusion of ice by the temperature for the reversible pathway.
[2] In arc welding, Argon is used because of its -
A.
Low reactivity with metal
B.
Ability to lower the melting point of the metal
C.
High flammability
D.
High calorific value
Ans:
Low reactivity with metal
Explanation :
In arc welding, Argon is used as a shielding gas because it is chemically inert and forms no compounds. At the high temperatures that welding requires, the metals being welded become highly reactive to the elements in the atmosphere. Contamination from these elements can lead to brittle welds and instability in the welding arc. So,argon and other inert gases are sprayed.
[3] Kinetics is the study of:
A.
The rate of chemical reaction
B.
How fast the reactions go
C.
The mechanisms and paths of the molecules take in joining from one reactant to products
D.
All of these are correct
Ans:
All of these are correct
Explanation :
In chemistry, the study of rates and mechanisms of chemical processes and, of the factors on which they depend, is called kinetics. is the study of how fast chemical reactions occur. It provides evidence for the mechanisms of chemical reactions and studies the most effective way of causing a reaction to occur. It studies reaction mechanisms, examining what path the reactants take in order to become the products, and provides a very detailed picture of which bonds are broken and formed during the course of a reaction.
[4] Superconductivity is a material property associated with -
A.
cooling a substance without a phase change
B.
frictionless liquid flow
C.
a loss of thermal resistance
D.
a loss of electrical resistance
Ans:
a loss of thermal resistance
Explanation :
Superconductivity is a phenomenon of exactly zero electrical resistance and expulsion of magnetic flux fields occurring in certain materials, called superconductors.
[5] What role does enzyme pepsin play?
A.
It converts fats into acids
B.
If converts fats into glycerol
C.
It converts proteins into peptones
D.
It converts starch into sugar
Ans:
It converts proteins into peptones
Explanation :
Pepsin is an endopeptidase that breaks down proteins into peptone and polypeptides. If is produced in the stomach and is one of the main digestive enzymes.
[6] Water gas is the mixture of –
A.
carbon dioxide and hydrogen
B.
carbon monoxide and nitrogen
C.
carbon monoxide and hydrogen
D.
carbon dioxide and nitrogen
Ans:
carbon monoxide and hydrogen
Explanation :
Water gas, a mixture of carbon monoxide and hydrogen, is produced by treating carbon (in the form of coke or coal) with steam at high temperatures.
[7] Hardness of the water is commonly measured in terms of -
A.
Calcium carbonate equivalents
B.
Calcium sulphate equivalents
C.
Magnesium carbonate equivalents
D.
Magnesium sulphate equivalents
Ans:
Calcium carbonate equivalents
Explanation :
0
[8] One property of ammonia is –
A.
It is insoluble in water
B.
it is a odourless gas
C.
It is a yellowish gas
D.
Its aqueous solution turns red litmus blue
Ans:
Its aqueous solution turns red litmus blue
Explanation :
The main use of litmus is to test whether a solution is acidic or basic. For instance, ammonia gas, which is alkaline, colours the red litmus paper blue.
[9] ‘Aerosol’ is -
A.
Suspended solid particles in air
B.
Pollutant gas, present in air
C.
Microbes, present in air
D.
Green house gas present in air
Ans:
Suspended solid particles in air
Explanation :
0
[10] Bridgmanite is –
A.
A bridge on the river Thames
B.
Name of a game
C.
Earth's most abundant mineral
D.
Name of a music
Ans:
Earth's most abundant mineral
Explanation :
Bridgmanite is the accepted name for the mineral silicate perovskite, (Mg,Fe)SiO3 the most common mineral on Earth. It was discovered in Tenham thandrite meteorite, where it associates with another polymorph of MgSiO3 substance - akimotoite.
[11] The molecular mass of a has is –
A.
twice its vapour pressure
B.
equal to its vapour pressure
C.
half its vapour pressure
D.
not related to its vapour pressure
Ans:
twice its vapour pressure
Explanation :
The molecular weight (molar mass) of any gas is the mass of one particle of that gas multiplie d by Avogadro's number. It is twice its vapor pressure since the molecular mass of any gas is twice its density in relation to hydrogen which has 2 atoms in one molecule.
[12] Carbon footprint can be reduced by –
A.
All of these
B.
Recycling waste materials
C.
Using energy efficient appliances
D.
Commuting by public transport
Ans:
All of these
Explanation :
A carbon footprint is historically defined as "the total sets of greenhouse gas emissions caused by an organization, event, product or person." The most common way to reduce the carbon footprint of humans is to Reduce, Reuse, Recycle, Refuse. Recycling waste materials, using energy efficient appliances and using public transportation for commutation can all serve to reduce greenhouse gas emissions and, thus, reduce Carbon footprint.
[13] Thermal electricity is generated by using which of these?
A.
Coal only
B.
Coal and Natural Gas only
C.
Coal, Natural Gas and Petroleum
D.
None of these
Ans:
Coal, Natural Gas and Petroleum
Explanation :
A thermal power station is a power plant in which heat energy is converted to electric power. Thermal power is producing using fossil fuel such as coal, natural gas or petroleum. More than 65% of India's electricity generation capacity comes from thermal power plants, with about 85% of the country's thermal power generation being coal-based.
[14] The mass number of a nucleus is –
A.
always less than its atomic number
B.
always more than its atomic number
C.
always equal to its atomic number
D.
sometimes more - and somtimes equal to its atomic number
Ans:
sometimes more - and somtimes equal to its atomic number
Explanation :
Mass number = protons or mass of electron (atomic number) + neutrons. So it is mostly greater than the atomic number. At best, it can be equal to the atomic number.
[15] Ionisation energy of nitrogen is greater than that of oxygen because nitrogen has –
A.
high bond dissociation energy
B.
smaller atomic radius
C.
stable half filled 2p sub level
D.
high nuclear charge
Ans:
stable half filled 2p sub level
Explanation :
Ionization energy is a measure of the ease in which atoms lose electrons and become positive ions.
[16] Graphite is used in nuclear reactors for-
A.
reducing the speed of fast neutrons
B.
cooling the reactor
C.
absorbing neutrons
D.
None of the above
Ans:
reducing the speed of fast neutrons
Explanation :
A graphite reactor is a nuclear reactor that uses carbon as a neutron moderator, which allows un- enriched uranium to be used as nuclear fuel.
[17] Bleaching powder is prepared by passing –
A.
Chlorine over slaked lime
B.
Oxygen over slaked lime
C.
Carbon dioxide over slaked lime
D.
Chlorine over quick lirne
Ans:
Chlorine over slaked lime
Explanation :
Calcium hypochlorite (bleaching powder) is manufactured by the calcium process: 2Cl2 + 2Ca(OH)2 (slaked lime) Ca(OCl)2 + CaCl2 + 2H2O. Bleaching powder is actually a mixture of calcium hypochlorite and the basic chloride with some slaked lime.
[18] Acid rain is caused due to pollution of atmosphere by –
A.
oxides of carbon and nitrogen
B.
oxides of nitrogen and sulphur
C.
oxides of nitrogen and phosphorus
D.
None of these
Ans:
oxides of nitrogen and sulphur
Explanation :
Acid rain is caused by emissions of Sulpfur Dioxide (SO2) and Nitrogen Oxide (NOx), which react with the water molecules in the atmosphere to produce acids.
[19] The working of a dry cell is based on -
A.
Decomposition reaction
B.
Spontaneous oxidation-reduction reaction
C.
Combination reaction.
D.
Electrolysis
Ans:
Electrolysis
Explanation :
A dry cell is a type of battery that uses a paste electrolyte, with only enough moisture to allow current to flow. It works in accordance with Faraday's law of electrolysis. It consists of an outer case made of zinc the negative electrode), a carbon rod in the center of the cell (the positive electrode), and the space between them is filled with an electrolyte paste.
[20] Which of the following is the correct sequence of countries in terms of maximum carbon dioxide emission?
A.
China, USA, European Union, India
B.
USA, India, China, European Union
C.
China, India, European Union, USA
D.
European Union, China, USA, India
Ans:
China, USA, European Union, India
Explanation :
According to the EDGAR database released by European Commission and Netherlands Environmental Assessment Agency in 2014, China, USA, European Union, India and Russia are the largest emitters of carbon emission (annual CO2 emissions estimates in thousands of CO3 tonnes) across the globe.
[21] Potassium Permanganate is used for purifying drinking water, because .
A.
It is a reducing agent
B.
It is an oxidising agent
C.
It is a sterilising agent
D.
It dissolves the impurities of water
Ans:
It is an oxidising agent
Explanation :
Potassium permanganate is a point-of-entry water treatment method that oxidizes dissolved iron, mancianese, and hydrogen sulfide into solid particles that are filtered out of the water. It can al so be used to control iron bacteria growth in wells. It is an oxidant, but a poor disinfectant.
[22] Oxide of sulphur present in the atmosphere are washed down by rains to cause –
A.
Depletion of fossil fuel reserves
B.
Eutrophication in lakes
C.
Lowering of pH of soil
D.
Industrial smog formation
Ans:
Depletion of fossil fuel reserves
Explanation :
The oxide of Sulphur (Sulphur Dioxide) is washed down on earth as acid rain. It makes the soil acidic by lowering its pH; this affects plants and animals adversely. Acid rain contains H+, SO42- ions which when added to the soil leaches the nutrients from the soil. Acid rain renders the river or even ocean water acidic, thereby affecting marine animals adversely. Changes in pH of fresh water affect the reproduction and survival or many species or fish.
[23] An emulsifier is an agent which –
A.
stabilises an emulsion
B.
aids the flocculation of an emulsion
C.
accelerates the dispersion
D.
homogenises an emulsion
Ans:
stabilises an emulsion
Explanation :
An emulsifier is a substance that stabilizes an emulsion by increasing its kinetic stability. One class of emulsifiers is known as "surface active substances", or surfactants. Many different emulsifiers are used in pharmacy to prepare emulsions such as creams and lotions. Common examples include emulsifying wax, cetearyl alcohol, polysorbate 20, and ceteareth 20. Sometimes the inner phase itself can act as an emulsifier, and the result is a nanoemulsion, where the inner state disperses into "nano-size" droplets within the outer phase.
[24] Hydrogen is not found in atmosphere because –
A.
it is highly inflammable
B.
it is the lightest gas
C.
it is absorbed by plants
D.
it immediately combines with oxygen to form water
Ans:
it is the lightest gas
Explanation :
Hydrogen is a chemical element with symbol H and atomic number 1. With an average atomic weight of 1.00794 u (1.007825 u for hydrogen-1), hydrogen is the lightest element and its monatomic form (H 1) is the most abundant chemical substance, constituting roughly 75% of the Universe's baryonic mass. Non-remnant stars are mainly composed of hydrogen in its plasma state. Air is the name given to the atmosphere used in breathing and photosynthesis.
[25] The mass number of a nucleus is -
A.
always less than its atomic number
B.
the sum of the number of protons and neutrons present in the nucleus
C.
always more than the atomic weight
D.
a fraction
Ans:
the sum of the number of protons and neutrons present in the nucleus
Explanation :
Mass number = protons or mass of electron (atomic number) + neutrons. So it is mostly greater than the atomic number. At best, it can be equal to the atomic number.
Explanation :
When water is frozen into ice, the temperature drops below 0°C. Since the entropy of the solid is less than that of the liquid, the entropy of the water (the system here) will decrease on freezing. The amount of decrease is found by dividing the heat of fusion of ice by the temperature for the reversible pathway.
[2] In arc welding, Argon is used because of its -
A.
Low reactivity with metal
B.
Ability to lower the melting point of the metal
C.
High flammability
D.
High calorific value
Ans:
Low reactivity with metal
Explanation :
In arc welding, Argon is used as a shielding gas because it is chemically inert and forms no compounds. At the high temperatures that welding requires, the metals being welded become highly reactive to the elements in the atmosphere. Contamination from these elements can lead to brittle welds and instability in the welding arc. So,argon and other inert gases are sprayed.
[3] Kinetics is the study of:
A.
The rate of chemical reaction
B.
How fast the reactions go
C.
The mechanisms and paths of the molecules take in joining from one reactant to products
D.
All of these are correct
Ans:
All of these are correct
Explanation :
In chemistry, the study of rates and mechanisms of chemical processes and, of the factors on which they depend, is called kinetics. is the study of how fast chemical reactions occur. It provides evidence for the mechanisms of chemical reactions and studies the most effective way of causing a reaction to occur. It studies reaction mechanisms, examining what path the reactants take in order to become the products, and provides a very detailed picture of which bonds are broken and formed during the course of a reaction.
[4] Superconductivity is a material property associated with -
A.
cooling a substance without a phase change
B.
frictionless liquid flow
C.
a loss of thermal resistance
D.
a loss of electrical resistance
Ans:
a loss of thermal resistance
Explanation :
Superconductivity is a phenomenon of exactly zero electrical resistance and expulsion of magnetic flux fields occurring in certain materials, called superconductors.
[5] What role does enzyme pepsin play?
A.
It converts fats into acids
B.
If converts fats into glycerol
C.
It converts proteins into peptones
D.
It converts starch into sugar
Ans:
It converts proteins into peptones
Explanation :
Pepsin is an endopeptidase that breaks down proteins into peptone and polypeptides. If is produced in the stomach and is one of the main digestive enzymes.
[6] Water gas is the mixture of –
A.
carbon dioxide and hydrogen
B.
carbon monoxide and nitrogen
C.
carbon monoxide and hydrogen
D.
carbon dioxide and nitrogen
Ans:
carbon monoxide and hydrogen
Explanation :
Water gas, a mixture of carbon monoxide and hydrogen, is produced by treating carbon (in the form of coke or coal) with steam at high temperatures.
[7] Hardness of the water is commonly measured in terms of -
A.
Calcium carbonate equivalents
B.
Calcium sulphate equivalents
C.
Magnesium carbonate equivalents
D.
Magnesium sulphate equivalents
Ans:
Calcium carbonate equivalents
Explanation :
0
[8] One property of ammonia is –
A.
It is insoluble in water
B.
it is a odourless gas
C.
It is a yellowish gas
D.
Its aqueous solution turns red litmus blue
Ans:
Its aqueous solution turns red litmus blue
Explanation :
The main use of litmus is to test whether a solution is acidic or basic. For instance, ammonia gas, which is alkaline, colours the red litmus paper blue.
[9] ‘Aerosol’ is -
A.
Suspended solid particles in air
B.
Pollutant gas, present in air
C.
Microbes, present in air
D.
Green house gas present in air
Ans:
Suspended solid particles in air
Explanation :
0
[10] Bridgmanite is –
A.
A bridge on the river Thames
B.
Name of a game
C.
Earth's most abundant mineral
D.
Name of a music
Ans:
Earth's most abundant mineral
Explanation :
Bridgmanite is the accepted name for the mineral silicate perovskite, (Mg,Fe)SiO3 the most common mineral on Earth. It was discovered in Tenham thandrite meteorite, where it associates with another polymorph of MgSiO3 substance - akimotoite.
[11] The molecular mass of a has is –
A.
twice its vapour pressure
B.
equal to its vapour pressure
C.
half its vapour pressure
D.
not related to its vapour pressure
Ans:
twice its vapour pressure
Explanation :
The molecular weight (molar mass) of any gas is the mass of one particle of that gas multiplie d by Avogadro's number. It is twice its vapor pressure since the molecular mass of any gas is twice its density in relation to hydrogen which has 2 atoms in one molecule.
[12] Carbon footprint can be reduced by –
A.
All of these
B.
Recycling waste materials
C.
Using energy efficient appliances
D.
Commuting by public transport
Ans:
All of these
Explanation :
A carbon footprint is historically defined as "the total sets of greenhouse gas emissions caused by an organization, event, product or person." The most common way to reduce the carbon footprint of humans is to Reduce, Reuse, Recycle, Refuse. Recycling waste materials, using energy efficient appliances and using public transportation for commutation can all serve to reduce greenhouse gas emissions and, thus, reduce Carbon footprint.
[13] Thermal electricity is generated by using which of these?
A.
Coal only
B.
Coal and Natural Gas only
C.
Coal, Natural Gas and Petroleum
D.
None of these
Ans:
Coal, Natural Gas and Petroleum
Explanation :
A thermal power station is a power plant in which heat energy is converted to electric power. Thermal power is producing using fossil fuel such as coal, natural gas or petroleum. More than 65% of India's electricity generation capacity comes from thermal power plants, with about 85% of the country's thermal power generation being coal-based.
[14] The mass number of a nucleus is –
A.
always less than its atomic number
B.
always more than its atomic number
C.
always equal to its atomic number
D.
sometimes more - and somtimes equal to its atomic number
Ans:
sometimes more - and somtimes equal to its atomic number
Explanation :
Mass number = protons or mass of electron (atomic number) + neutrons. So it is mostly greater than the atomic number. At best, it can be equal to the atomic number.
[15] Ionisation energy of nitrogen is greater than that of oxygen because nitrogen has –
A.
high bond dissociation energy
B.
smaller atomic radius
C.
stable half filled 2p sub level
D.
high nuclear charge
Ans:
stable half filled 2p sub level
Explanation :
Ionization energy is a measure of the ease in which atoms lose electrons and become positive ions.
[16] Graphite is used in nuclear reactors for-
A.
reducing the speed of fast neutrons
B.
cooling the reactor
C.
absorbing neutrons
D.
None of the above
Ans:
reducing the speed of fast neutrons
Explanation :
A graphite reactor is a nuclear reactor that uses carbon as a neutron moderator, which allows un- enriched uranium to be used as nuclear fuel.
[17] Bleaching powder is prepared by passing –
A.
Chlorine over slaked lime
B.
Oxygen over slaked lime
C.
Carbon dioxide over slaked lime
D.
Chlorine over quick lirne
Ans:
Chlorine over slaked lime
Explanation :
Calcium hypochlorite (bleaching powder) is manufactured by the calcium process: 2Cl2 + 2Ca(OH)2 (slaked lime) Ca(OCl)2 + CaCl2 + 2H2O. Bleaching powder is actually a mixture of calcium hypochlorite and the basic chloride with some slaked lime.
[18] Acid rain is caused due to pollution of atmosphere by –
A.
oxides of carbon and nitrogen
B.
oxides of nitrogen and sulphur
C.
oxides of nitrogen and phosphorus
D.
None of these
Ans:
oxides of nitrogen and sulphur
Explanation :
Acid rain is caused by emissions of Sulpfur Dioxide (SO2) and Nitrogen Oxide (NOx), which react with the water molecules in the atmosphere to produce acids.
[19] The working of a dry cell is based on -
A.
Decomposition reaction
B.
Spontaneous oxidation-reduction reaction
C.
Combination reaction.
D.
Electrolysis
Ans:
Electrolysis
Explanation :
A dry cell is a type of battery that uses a paste electrolyte, with only enough moisture to allow current to flow. It works in accordance with Faraday's law of electrolysis. It consists of an outer case made of zinc the negative electrode), a carbon rod in the center of the cell (the positive electrode), and the space between them is filled with an electrolyte paste.
[20] Which of the following is the correct sequence of countries in terms of maximum carbon dioxide emission?
A.
China, USA, European Union, India
B.
USA, India, China, European Union
C.
China, India, European Union, USA
D.
European Union, China, USA, India
Ans:
China, USA, European Union, India
Explanation :
According to the EDGAR database released by European Commission and Netherlands Environmental Assessment Agency in 2014, China, USA, European Union, India and Russia are the largest emitters of carbon emission (annual CO2 emissions estimates in thousands of CO3 tonnes) across the globe.
[21] Potassium Permanganate is used for purifying drinking water, because .
A.
It is a reducing agent
B.
It is an oxidising agent
C.
It is a sterilising agent
D.
It dissolves the impurities of water
Ans:
It is an oxidising agent
Explanation :
Potassium permanganate is a point-of-entry water treatment method that oxidizes dissolved iron, mancianese, and hydrogen sulfide into solid particles that are filtered out of the water. It can al so be used to control iron bacteria growth in wells. It is an oxidant, but a poor disinfectant.
[22] Oxide of sulphur present in the atmosphere are washed down by rains to cause –
A.
Depletion of fossil fuel reserves
B.
Eutrophication in lakes
C.
Lowering of pH of soil
D.
Industrial smog formation
Ans:
Depletion of fossil fuel reserves
Explanation :
The oxide of Sulphur (Sulphur Dioxide) is washed down on earth as acid rain. It makes the soil acidic by lowering its pH; this affects plants and animals adversely. Acid rain contains H+, SO42- ions which when added to the soil leaches the nutrients from the soil. Acid rain renders the river or even ocean water acidic, thereby affecting marine animals adversely. Changes in pH of fresh water affect the reproduction and survival or many species or fish.
[23] An emulsifier is an agent which –
A.
stabilises an emulsion
B.
aids the flocculation of an emulsion
C.
accelerates the dispersion
D.
homogenises an emulsion
Ans:
stabilises an emulsion
Explanation :
An emulsifier is a substance that stabilizes an emulsion by increasing its kinetic stability. One class of emulsifiers is known as "surface active substances", or surfactants. Many different emulsifiers are used in pharmacy to prepare emulsions such as creams and lotions. Common examples include emulsifying wax, cetearyl alcohol, polysorbate 20, and ceteareth 20. Sometimes the inner phase itself can act as an emulsifier, and the result is a nanoemulsion, where the inner state disperses into "nano-size" droplets within the outer phase.
[24] Hydrogen is not found in atmosphere because –
A.
it is highly inflammable
B.
it is the lightest gas
C.
it is absorbed by plants
D.
it immediately combines with oxygen to form water
Ans:
it is the lightest gas
Explanation :
Hydrogen is a chemical element with symbol H and atomic number 1. With an average atomic weight of 1.00794 u (1.007825 u for hydrogen-1), hydrogen is the lightest element and its monatomic form (H 1) is the most abundant chemical substance, constituting roughly 75% of the Universe's baryonic mass. Non-remnant stars are mainly composed of hydrogen in its plasma state. Air is the name given to the atmosphere used in breathing and photosynthesis.
[25] The mass number of a nucleus is -
A.
always less than its atomic number
B.
the sum of the number of protons and neutrons present in the nucleus
C.
always more than the atomic weight
D.
a fraction
Ans:
the sum of the number of protons and neutrons present in the nucleus
Explanation :
Mass number = protons or mass of electron (atomic number) + neutrons. So it is mostly greater than the atomic number. At best, it can be equal to the atomic number.
Explanation :
In chemistry, the study of rates and mechanisms of chemical processes and, of the factors on which they depend, is called kinetics. is the study of how fast chemical reactions occur. It provides evidence for the mechanisms of chemical reactions and studies the most effective way of causing a reaction to occur. It studies reaction mechanisms, examining what path the reactants take in order to become the products, and provides a very detailed picture of which bonds are broken and formed during the course of a reaction.
[4] Superconductivity is a material property associated with -
A.
cooling a substance without a phase change
B.
frictionless liquid flow
C.
a loss of thermal resistance
D.
a loss of electrical resistance
Ans:
a loss of thermal resistance
Explanation :
Superconductivity is a phenomenon of exactly zero electrical resistance and expulsion of magnetic flux fields occurring in certain materials, called superconductors.
[5] What role does enzyme pepsin play?
A.
It converts fats into acids
B.
If converts fats into glycerol
C.
It converts proteins into peptones
D.
It converts starch into sugar
Ans:
It converts proteins into peptones
Explanation :
Pepsin is an endopeptidase that breaks down proteins into peptone and polypeptides. If is produced in the stomach and is one of the main digestive enzymes.
[6] Water gas is the mixture of –
A.
carbon dioxide and hydrogen
B.
carbon monoxide and nitrogen
C.
carbon monoxide and hydrogen
D.
carbon dioxide and nitrogen
Ans:
carbon monoxide and hydrogen
Explanation :
Water gas, a mixture of carbon monoxide and hydrogen, is produced by treating carbon (in the form of coke or coal) with steam at high temperatures.
[7] Hardness of the water is commonly measured in terms of -
A.
Calcium carbonate equivalents
B.
Calcium sulphate equivalents
C.
Magnesium carbonate equivalents
D.
Magnesium sulphate equivalents
Ans:
Calcium carbonate equivalents
Explanation :
0
[8] One property of ammonia is –
A.
It is insoluble in water
B.
it is a odourless gas
C.
It is a yellowish gas
D.
Its aqueous solution turns red litmus blue
Ans:
Its aqueous solution turns red litmus blue
Explanation :
The main use of litmus is to test whether a solution is acidic or basic. For instance, ammonia gas, which is alkaline, colours the red litmus paper blue.
[9] ‘Aerosol’ is -
A.
Suspended solid particles in air
B.
Pollutant gas, present in air
C.
Microbes, present in air
D.
Green house gas present in air
Ans:
Suspended solid particles in air
Explanation :
0
[10] Bridgmanite is –
A.
A bridge on the river Thames
B.
Name of a game
C.
Earth's most abundant mineral
D.
Name of a music
Ans:
Earth's most abundant mineral
Explanation :
Bridgmanite is the accepted name for the mineral silicate perovskite, (Mg,Fe)SiO3 the most common mineral on Earth. It was discovered in Tenham thandrite meteorite, where it associates with another polymorph of MgSiO3 substance - akimotoite.
[11] The molecular mass of a has is –
A.
twice its vapour pressure
B.
equal to its vapour pressure
C.
half its vapour pressure
D.
not related to its vapour pressure
Ans:
twice its vapour pressure
Explanation :
The molecular weight (molar mass) of any gas is the mass of one particle of that gas multiplie d by Avogadro's number. It is twice its vapor pressure since the molecular mass of any gas is twice its density in relation to hydrogen which has 2 atoms in one molecule.
[12] Carbon footprint can be reduced by –
A.
All of these
B.
Recycling waste materials
C.
Using energy efficient appliances
D.
Commuting by public transport
Ans:
All of these
Explanation :
A carbon footprint is historically defined as "the total sets of greenhouse gas emissions caused by an organization, event, product or person." The most common way to reduce the carbon footprint of humans is to Reduce, Reuse, Recycle, Refuse. Recycling waste materials, using energy efficient appliances and using public transportation for commutation can all serve to reduce greenhouse gas emissions and, thus, reduce Carbon footprint.
[13] Thermal electricity is generated by using which of these?
A.
Coal only
B.
Coal and Natural Gas only
C.
Coal, Natural Gas and Petroleum
D.
None of these
Ans:
Coal, Natural Gas and Petroleum
Explanation :
A thermal power station is a power plant in which heat energy is converted to electric power. Thermal power is producing using fossil fuel such as coal, natural gas or petroleum. More than 65% of India's electricity generation capacity comes from thermal power plants, with about 85% of the country's thermal power generation being coal-based.
[14] The mass number of a nucleus is –
A.
always less than its atomic number
B.
always more than its atomic number
C.
always equal to its atomic number
D.
sometimes more - and somtimes equal to its atomic number
Ans:
sometimes more - and somtimes equal to its atomic number
Explanation :
Mass number = protons or mass of electron (atomic number) + neutrons. So it is mostly greater than the atomic number. At best, it can be equal to the atomic number.
[15] Ionisation energy of nitrogen is greater than that of oxygen because nitrogen has –
A.
high bond dissociation energy
B.
smaller atomic radius
C.
stable half filled 2p sub level
D.
high nuclear charge
Ans:
stable half filled 2p sub level
Explanation :
Ionization energy is a measure of the ease in which atoms lose electrons and become positive ions.
[16] Graphite is used in nuclear reactors for-
A.
reducing the speed of fast neutrons
B.
cooling the reactor
C.
absorbing neutrons
D.
None of the above
Ans:
reducing the speed of fast neutrons
Explanation :
A graphite reactor is a nuclear reactor that uses carbon as a neutron moderator, which allows un- enriched uranium to be used as nuclear fuel.
[17] Bleaching powder is prepared by passing –
A.
Chlorine over slaked lime
B.
Oxygen over slaked lime
C.
Carbon dioxide over slaked lime
D.
Chlorine over quick lirne
Ans:
Chlorine over slaked lime
Explanation :
Calcium hypochlorite (bleaching powder) is manufactured by the calcium process: 2Cl2 + 2Ca(OH)2 (slaked lime) Ca(OCl)2 + CaCl2 + 2H2O. Bleaching powder is actually a mixture of calcium hypochlorite and the basic chloride with some slaked lime.
[18] Acid rain is caused due to pollution of atmosphere by –
A.
oxides of carbon and nitrogen
B.
oxides of nitrogen and sulphur
C.
oxides of nitrogen and phosphorus
D.
None of these
Ans:
oxides of nitrogen and sulphur
Explanation :
Acid rain is caused by emissions of Sulpfur Dioxide (SO2) and Nitrogen Oxide (NOx), which react with the water molecules in the atmosphere to produce acids.
[19] The working of a dry cell is based on -
A.
Decomposition reaction
B.
Spontaneous oxidation-reduction reaction
C.
Combination reaction.
D.
Electrolysis
Ans:
Electrolysis
Explanation :
A dry cell is a type of battery that uses a paste electrolyte, with only enough moisture to allow current to flow. It works in accordance with Faraday's law of electrolysis. It consists of an outer case made of zinc the negative electrode), a carbon rod in the center of the cell (the positive electrode), and the space between them is filled with an electrolyte paste.
[20] Which of the following is the correct sequence of countries in terms of maximum carbon dioxide emission?
A.
China, USA, European Union, India
B.
USA, India, China, European Union
C.
China, India, European Union, USA
D.
European Union, China, USA, India
Ans:
China, USA, European Union, India
Explanation :
According to the EDGAR database released by European Commission and Netherlands Environmental Assessment Agency in 2014, China, USA, European Union, India and Russia are the largest emitters of carbon emission (annual CO2 emissions estimates in thousands of CO3 tonnes) across the globe.
[21] Potassium Permanganate is used for purifying drinking water, because .
A.
It is a reducing agent
B.
It is an oxidising agent
C.
It is a sterilising agent
D.
It dissolves the impurities of water
Ans:
It is an oxidising agent
Explanation :
Potassium permanganate is a point-of-entry water treatment method that oxidizes dissolved iron, mancianese, and hydrogen sulfide into solid particles that are filtered out of the water. It can al so be used to control iron bacteria growth in wells. It is an oxidant, but a poor disinfectant.
[22] Oxide of sulphur present in the atmosphere are washed down by rains to cause –
A.
Depletion of fossil fuel reserves
B.
Eutrophication in lakes
C.
Lowering of pH of soil
D.
Industrial smog formation
Ans:
Depletion of fossil fuel reserves
Explanation :
The oxide of Sulphur (Sulphur Dioxide) is washed down on earth as acid rain. It makes the soil acidic by lowering its pH; this affects plants and animals adversely. Acid rain contains H+, SO42- ions which when added to the soil leaches the nutrients from the soil. Acid rain renders the river or even ocean water acidic, thereby affecting marine animals adversely. Changes in pH of fresh water affect the reproduction and survival or many species or fish.
[23] An emulsifier is an agent which –
A.
stabilises an emulsion
B.
aids the flocculation of an emulsion
C.
accelerates the dispersion
D.
homogenises an emulsion
Ans:
stabilises an emulsion
Explanation :
An emulsifier is a substance that stabilizes an emulsion by increasing its kinetic stability. One class of emulsifiers is known as "surface active substances", or surfactants. Many different emulsifiers are used in pharmacy to prepare emulsions such as creams and lotions. Common examples include emulsifying wax, cetearyl alcohol, polysorbate 20, and ceteareth 20. Sometimes the inner phase itself can act as an emulsifier, and the result is a nanoemulsion, where the inner state disperses into "nano-size" droplets within the outer phase.
[24] Hydrogen is not found in atmosphere because –
A.
it is highly inflammable
B.
it is the lightest gas
C.
it is absorbed by plants
D.
it immediately combines with oxygen to form water
Ans:
it is the lightest gas
Explanation :
Hydrogen is a chemical element with symbol H and atomic number 1. With an average atomic weight of 1.00794 u (1.007825 u for hydrogen-1), hydrogen is the lightest element and its monatomic form (H 1) is the most abundant chemical substance, constituting roughly 75% of the Universe's baryonic mass. Non-remnant stars are mainly composed of hydrogen in its plasma state. Air is the name given to the atmosphere used in breathing and photosynthesis.
[25] The mass number of a nucleus is -
A.
always less than its atomic number
B.
the sum of the number of protons and neutrons present in the nucleus
C.
always more than the atomic weight
D.
a fraction
Ans:
the sum of the number of protons and neutrons present in the nucleus
Explanation :
Mass number = protons or mass of electron (atomic number) + neutrons. So it is mostly greater than the atomic number. At best, it can be equal to the atomic number.
Explanation :
Pepsin is an endopeptidase that breaks down proteins into peptone and polypeptides. If is produced in the stomach and is one of the main digestive enzymes.
[6] Water gas is the mixture of –
A.
carbon dioxide and hydrogen
B.
carbon monoxide and nitrogen
C.
carbon monoxide and hydrogen
D.
carbon dioxide and nitrogen
Ans:
carbon monoxide and hydrogen
Explanation :
Water gas, a mixture of carbon monoxide and hydrogen, is produced by treating carbon (in the form of coke or coal) with steam at high temperatures.
[7] Hardness of the water is commonly measured in terms of -
A.
Calcium carbonate equivalents
B.
Calcium sulphate equivalents
C.
Magnesium carbonate equivalents
D.
Magnesium sulphate equivalents
Ans:
Calcium carbonate equivalents
Explanation :
0
[8] One property of ammonia is –
A.
It is insoluble in water
B.
it is a odourless gas
C.
It is a yellowish gas
D.
Its aqueous solution turns red litmus blue
Ans:
Its aqueous solution turns red litmus blue
Explanation :
The main use of litmus is to test whether a solution is acidic or basic. For instance, ammonia gas, which is alkaline, colours the red litmus paper blue.
[9] ‘Aerosol’ is -
A.
Suspended solid particles in air
B.
Pollutant gas, present in air
C.
Microbes, present in air
D.
Green house gas present in air
Ans:
Suspended solid particles in air
Explanation :
0
[10] Bridgmanite is –
A.
A bridge on the river Thames
B.
Name of a game
C.
Earth's most abundant mineral
D.
Name of a music
Ans:
Earth's most abundant mineral
Explanation :
Bridgmanite is the accepted name for the mineral silicate perovskite, (Mg,Fe)SiO3 the most common mineral on Earth. It was discovered in Tenham thandrite meteorite, where it associates with another polymorph of MgSiO3 substance - akimotoite.
[11] The molecular mass of a has is –
A.
twice its vapour pressure
B.
equal to its vapour pressure
C.
half its vapour pressure
D.
not related to its vapour pressure
Ans:
twice its vapour pressure
Explanation :
The molecular weight (molar mass) of any gas is the mass of one particle of that gas multiplie d by Avogadro's number. It is twice its vapor pressure since the molecular mass of any gas is twice its density in relation to hydrogen which has 2 atoms in one molecule.
[12] Carbon footprint can be reduced by –
A.
All of these
B.
Recycling waste materials
C.
Using energy efficient appliances
D.
Commuting by public transport
Ans:
All of these
Explanation :
A carbon footprint is historically defined as "the total sets of greenhouse gas emissions caused by an organization, event, product or person." The most common way to reduce the carbon footprint of humans is to Reduce, Reuse, Recycle, Refuse. Recycling waste materials, using energy efficient appliances and using public transportation for commutation can all serve to reduce greenhouse gas emissions and, thus, reduce Carbon footprint.
[13] Thermal electricity is generated by using which of these?
A.
Coal only
B.
Coal and Natural Gas only
C.
Coal, Natural Gas and Petroleum
D.
None of these
Ans:
Coal, Natural Gas and Petroleum
Explanation :
A thermal power station is a power plant in which heat energy is converted to electric power. Thermal power is producing using fossil fuel such as coal, natural gas or petroleum. More than 65% of India's electricity generation capacity comes from thermal power plants, with about 85% of the country's thermal power generation being coal-based.
[14] The mass number of a nucleus is –
A.
always less than its atomic number
B.
always more than its atomic number
C.
always equal to its atomic number
D.
sometimes more - and somtimes equal to its atomic number
Ans:
sometimes more - and somtimes equal to its atomic number
Explanation :
Mass number = protons or mass of electron (atomic number) + neutrons. So it is mostly greater than the atomic number. At best, it can be equal to the atomic number.
[15] Ionisation energy of nitrogen is greater than that of oxygen because nitrogen has –
A.
high bond dissociation energy
B.
smaller atomic radius
C.
stable half filled 2p sub level
D.
high nuclear charge
Ans:
stable half filled 2p sub level
Explanation :
Ionization energy is a measure of the ease in which atoms lose electrons and become positive ions.
[16] Graphite is used in nuclear reactors for-
A.
reducing the speed of fast neutrons
B.
cooling the reactor
C.
absorbing neutrons
D.
None of the above
Ans:
reducing the speed of fast neutrons
Explanation :
A graphite reactor is a nuclear reactor that uses carbon as a neutron moderator, which allows un- enriched uranium to be used as nuclear fuel.
[17] Bleaching powder is prepared by passing –
A.
Chlorine over slaked lime
B.
Oxygen over slaked lime
C.
Carbon dioxide over slaked lime
D.
Chlorine over quick lirne
Ans:
Chlorine over slaked lime
Explanation :
Calcium hypochlorite (bleaching powder) is manufactured by the calcium process: 2Cl2 + 2Ca(OH)2 (slaked lime) Ca(OCl)2 + CaCl2 + 2H2O. Bleaching powder is actually a mixture of calcium hypochlorite and the basic chloride with some slaked lime.
[18] Acid rain is caused due to pollution of atmosphere by –
A.
oxides of carbon and nitrogen
B.
oxides of nitrogen and sulphur
C.
oxides of nitrogen and phosphorus
D.
None of these
Ans:
oxides of nitrogen and sulphur
Explanation :
Acid rain is caused by emissions of Sulpfur Dioxide (SO2) and Nitrogen Oxide (NOx), which react with the water molecules in the atmosphere to produce acids.
[19] The working of a dry cell is based on -
A.
Decomposition reaction
B.
Spontaneous oxidation-reduction reaction
C.
Combination reaction.
D.
Electrolysis
Ans:
Electrolysis
Explanation :
A dry cell is a type of battery that uses a paste electrolyte, with only enough moisture to allow current to flow. It works in accordance with Faraday's law of electrolysis. It consists of an outer case made of zinc the negative electrode), a carbon rod in the center of the cell (the positive electrode), and the space between them is filled with an electrolyte paste.
[20] Which of the following is the correct sequence of countries in terms of maximum carbon dioxide emission?
A.
China, USA, European Union, India
B.
USA, India, China, European Union
C.
China, India, European Union, USA
D.
European Union, China, USA, India
Ans:
China, USA, European Union, India
Explanation :
According to the EDGAR database released by European Commission and Netherlands Environmental Assessment Agency in 2014, China, USA, European Union, India and Russia are the largest emitters of carbon emission (annual CO2 emissions estimates in thousands of CO3 tonnes) across the globe.
[21] Potassium Permanganate is used for purifying drinking water, because .
A.
It is a reducing agent
B.
It is an oxidising agent
C.
It is a sterilising agent
D.
It dissolves the impurities of water
Ans:
It is an oxidising agent
Explanation :
Potassium permanganate is a point-of-entry water treatment method that oxidizes dissolved iron, mancianese, and hydrogen sulfide into solid particles that are filtered out of the water. It can al so be used to control iron bacteria growth in wells. It is an oxidant, but a poor disinfectant.
[22] Oxide of sulphur present in the atmosphere are washed down by rains to cause –
A.
Depletion of fossil fuel reserves
B.
Eutrophication in lakes
C.
Lowering of pH of soil
D.
Industrial smog formation
Ans:
Depletion of fossil fuel reserves
Explanation :
The oxide of Sulphur (Sulphur Dioxide) is washed down on earth as acid rain. It makes the soil acidic by lowering its pH; this affects plants and animals adversely. Acid rain contains H+, SO42- ions which when added to the soil leaches the nutrients from the soil. Acid rain renders the river or even ocean water acidic, thereby affecting marine animals adversely. Changes in pH of fresh water affect the reproduction and survival or many species or fish.
[23] An emulsifier is an agent which –
A.
stabilises an emulsion
B.
aids the flocculation of an emulsion
C.
accelerates the dispersion
D.
homogenises an emulsion
Ans:
stabilises an emulsion
Explanation :
An emulsifier is a substance that stabilizes an emulsion by increasing its kinetic stability. One class of emulsifiers is known as "surface active substances", or surfactants. Many different emulsifiers are used in pharmacy to prepare emulsions such as creams and lotions. Common examples include emulsifying wax, cetearyl alcohol, polysorbate 20, and ceteareth 20. Sometimes the inner phase itself can act as an emulsifier, and the result is a nanoemulsion, where the inner state disperses into "nano-size" droplets within the outer phase.
[24] Hydrogen is not found in atmosphere because –
A.
it is highly inflammable
B.
it is the lightest gas
C.
it is absorbed by plants
D.
it immediately combines with oxygen to form water
Ans:
it is the lightest gas
Explanation :
Hydrogen is a chemical element with symbol H and atomic number 1. With an average atomic weight of 1.00794 u (1.007825 u for hydrogen-1), hydrogen is the lightest element and its monatomic form (H 1) is the most abundant chemical substance, constituting roughly 75% of the Universe's baryonic mass. Non-remnant stars are mainly composed of hydrogen in its plasma state. Air is the name given to the atmosphere used in breathing and photosynthesis.
[25] The mass number of a nucleus is -
A.
always less than its atomic number
B.
the sum of the number of protons and neutrons present in the nucleus
C.
always more than the atomic weight
D.
a fraction
Ans:
the sum of the number of protons and neutrons present in the nucleus
Explanation :
Mass number = protons or mass of electron (atomic number) + neutrons. So it is mostly greater than the atomic number. At best, it can be equal to the atomic number.
Explanation :
0
[8] One property of ammonia is –
A.
It is insoluble in water
B.
it is a odourless gas
C.
It is a yellowish gas
D.
Its aqueous solution turns red litmus blue
Ans:
Its aqueous solution turns red litmus blue
Explanation :
The main use of litmus is to test whether a solution is acidic or basic. For instance, ammonia gas, which is alkaline, colours the red litmus paper blue.
[9] ‘Aerosol’ is -
A.
Suspended solid particles in air
B.
Pollutant gas, present in air
C.
Microbes, present in air
D.
Green house gas present in air
Ans:
Suspended solid particles in air
Explanation :
0
[10] Bridgmanite is –
A.
A bridge on the river Thames
B.
Name of a game
C.
Earth's most abundant mineral
D.
Name of a music
Ans:
Earth's most abundant mineral
Explanation :
Bridgmanite is the accepted name for the mineral silicate perovskite, (Mg,Fe)SiO3 the most common mineral on Earth. It was discovered in Tenham thandrite meteorite, where it associates with another polymorph of MgSiO3 substance - akimotoite.
[11] The molecular mass of a has is –
A.
twice its vapour pressure
B.
equal to its vapour pressure
C.
half its vapour pressure
D.
not related to its vapour pressure
Ans:
twice its vapour pressure
Explanation :
The molecular weight (molar mass) of any gas is the mass of one particle of that gas multiplie d by Avogadro's number. It is twice its vapor pressure since the molecular mass of any gas is twice its density in relation to hydrogen which has 2 atoms in one molecule.
[12] Carbon footprint can be reduced by –
A.
All of these
B.
Recycling waste materials
C.
Using energy efficient appliances
D.
Commuting by public transport
Ans:
All of these
Explanation :
A carbon footprint is historically defined as "the total sets of greenhouse gas emissions caused by an organization, event, product or person." The most common way to reduce the carbon footprint of humans is to Reduce, Reuse, Recycle, Refuse. Recycling waste materials, using energy efficient appliances and using public transportation for commutation can all serve to reduce greenhouse gas emissions and, thus, reduce Carbon footprint.
[13] Thermal electricity is generated by using which of these?
A.
Coal only
B.
Coal and Natural Gas only
C.
Coal, Natural Gas and Petroleum
D.
None of these
Ans:
Coal, Natural Gas and Petroleum
Explanation :
A thermal power station is a power plant in which heat energy is converted to electric power. Thermal power is producing using fossil fuel such as coal, natural gas or petroleum. More than 65% of India's electricity generation capacity comes from thermal power plants, with about 85% of the country's thermal power generation being coal-based.
[14] The mass number of a nucleus is –
A.
always less than its atomic number
B.
always more than its atomic number
C.
always equal to its atomic number
D.
sometimes more - and somtimes equal to its atomic number
Ans:
sometimes more - and somtimes equal to its atomic number
Explanation :
Mass number = protons or mass of electron (atomic number) + neutrons. So it is mostly greater than the atomic number. At best, it can be equal to the atomic number.
[15] Ionisation energy of nitrogen is greater than that of oxygen because nitrogen has –
A.
high bond dissociation energy
B.
smaller atomic radius
C.
stable half filled 2p sub level
D.
high nuclear charge
Ans:
stable half filled 2p sub level
Explanation :
Ionization energy is a measure of the ease in which atoms lose electrons and become positive ions.
[16] Graphite is used in nuclear reactors for-
A.
reducing the speed of fast neutrons
B.
cooling the reactor
C.
absorbing neutrons
D.
None of the above
Ans:
reducing the speed of fast neutrons
Explanation :
A graphite reactor is a nuclear reactor that uses carbon as a neutron moderator, which allows un- enriched uranium to be used as nuclear fuel.
[17] Bleaching powder is prepared by passing –
A.
Chlorine over slaked lime
B.
Oxygen over slaked lime
C.
Carbon dioxide over slaked lime
D.
Chlorine over quick lirne
Ans:
Chlorine over slaked lime
Explanation :
Calcium hypochlorite (bleaching powder) is manufactured by the calcium process: 2Cl2 + 2Ca(OH)2 (slaked lime) Ca(OCl)2 + CaCl2 + 2H2O. Bleaching powder is actually a mixture of calcium hypochlorite and the basic chloride with some slaked lime.
[18] Acid rain is caused due to pollution of atmosphere by –
A.
oxides of carbon and nitrogen
B.
oxides of nitrogen and sulphur
C.
oxides of nitrogen and phosphorus
D.
None of these
Ans:
oxides of nitrogen and sulphur
Explanation :
Acid rain is caused by emissions of Sulpfur Dioxide (SO2) and Nitrogen Oxide (NOx), which react with the water molecules in the atmosphere to produce acids.
[19] The working of a dry cell is based on -
A.
Decomposition reaction
B.
Spontaneous oxidation-reduction reaction
C.
Combination reaction.
D.
Electrolysis
Ans:
Electrolysis
Explanation :
A dry cell is a type of battery that uses a paste electrolyte, with only enough moisture to allow current to flow. It works in accordance with Faraday's law of electrolysis. It consists of an outer case made of zinc the negative electrode), a carbon rod in the center of the cell (the positive electrode), and the space between them is filled with an electrolyte paste.
[20] Which of the following is the correct sequence of countries in terms of maximum carbon dioxide emission?
A.
China, USA, European Union, India
B.
USA, India, China, European Union
C.
China, India, European Union, USA
D.
European Union, China, USA, India
Ans:
China, USA, European Union, India
Explanation :
According to the EDGAR database released by European Commission and Netherlands Environmental Assessment Agency in 2014, China, USA, European Union, India and Russia are the largest emitters of carbon emission (annual CO2 emissions estimates in thousands of CO3 tonnes) across the globe.
[21] Potassium Permanganate is used for purifying drinking water, because .
A.
It is a reducing agent
B.
It is an oxidising agent
C.
It is a sterilising agent
D.
It dissolves the impurities of water
Ans:
It is an oxidising agent
Explanation :
Potassium permanganate is a point-of-entry water treatment method that oxidizes dissolved iron, mancianese, and hydrogen sulfide into solid particles that are filtered out of the water. It can al so be used to control iron bacteria growth in wells. It is an oxidant, but a poor disinfectant.
[22] Oxide of sulphur present in the atmosphere are washed down by rains to cause –
A.
Depletion of fossil fuel reserves
B.
Eutrophication in lakes
C.
Lowering of pH of soil
D.
Industrial smog formation
Ans:
Depletion of fossil fuel reserves
Explanation :
The oxide of Sulphur (Sulphur Dioxide) is washed down on earth as acid rain. It makes the soil acidic by lowering its pH; this affects plants and animals adversely. Acid rain contains H+, SO42- ions which when added to the soil leaches the nutrients from the soil. Acid rain renders the river or even ocean water acidic, thereby affecting marine animals adversely. Changes in pH of fresh water affect the reproduction and survival or many species or fish.
[23] An emulsifier is an agent which –
A.
stabilises an emulsion
B.
aids the flocculation of an emulsion
C.
accelerates the dispersion
D.
homogenises an emulsion
Ans:
stabilises an emulsion
Explanation :
An emulsifier is a substance that stabilizes an emulsion by increasing its kinetic stability. One class of emulsifiers is known as "surface active substances", or surfactants. Many different emulsifiers are used in pharmacy to prepare emulsions such as creams and lotions. Common examples include emulsifying wax, cetearyl alcohol, polysorbate 20, and ceteareth 20. Sometimes the inner phase itself can act as an emulsifier, and the result is a nanoemulsion, where the inner state disperses into "nano-size" droplets within the outer phase.
[24] Hydrogen is not found in atmosphere because –
A.
it is highly inflammable
B.
it is the lightest gas
C.
it is absorbed by plants
D.
it immediately combines with oxygen to form water
Ans:
it is the lightest gas
Explanation :
Hydrogen is a chemical element with symbol H and atomic number 1. With an average atomic weight of 1.00794 u (1.007825 u for hydrogen-1), hydrogen is the lightest element and its monatomic form (H 1) is the most abundant chemical substance, constituting roughly 75% of the Universe's baryonic mass. Non-remnant stars are mainly composed of hydrogen in its plasma state. Air is the name given to the atmosphere used in breathing and photosynthesis.
[25] The mass number of a nucleus is -
A.
always less than its atomic number
B.
the sum of the number of protons and neutrons present in the nucleus
C.
always more than the atomic weight
D.
a fraction
Ans:
the sum of the number of protons and neutrons present in the nucleus
Explanation :
Mass number = protons or mass of electron (atomic number) + neutrons. So it is mostly greater than the atomic number. At best, it can be equal to the atomic number.
Explanation :
0
[10] Bridgmanite is –
A.
A bridge on the river Thames
B.
Name of a game
C.
Earth's most abundant mineral
D.
Name of a music
Ans:
Earth's most abundant mineral
Explanation :
Bridgmanite is the accepted name for the mineral silicate perovskite, (Mg,Fe)SiO3 the most common mineral on Earth. It was discovered in Tenham thandrite meteorite, where it associates with another polymorph of MgSiO3 substance - akimotoite.
[11] The molecular mass of a has is –
A.
twice its vapour pressure
B.
equal to its vapour pressure
C.
half its vapour pressure
D.
not related to its vapour pressure
Ans:
twice its vapour pressure
Explanation :
The molecular weight (molar mass) of any gas is the mass of one particle of that gas multiplie d by Avogadro's number. It is twice its vapor pressure since the molecular mass of any gas is twice its density in relation to hydrogen which has 2 atoms in one molecule.
[12] Carbon footprint can be reduced by –
A.
All of these
B.
Recycling waste materials
C.
Using energy efficient appliances
D.
Commuting by public transport
Ans:
All of these
Explanation :
A carbon footprint is historically defined as "the total sets of greenhouse gas emissions caused by an organization, event, product or person." The most common way to reduce the carbon footprint of humans is to Reduce, Reuse, Recycle, Refuse. Recycling waste materials, using energy efficient appliances and using public transportation for commutation can all serve to reduce greenhouse gas emissions and, thus, reduce Carbon footprint.
[13] Thermal electricity is generated by using which of these?
A.
Coal only
B.
Coal and Natural Gas only
C.
Coal, Natural Gas and Petroleum
D.
None of these
Ans:
Coal, Natural Gas and Petroleum
Explanation :
A thermal power station is a power plant in which heat energy is converted to electric power. Thermal power is producing using fossil fuel such as coal, natural gas or petroleum. More than 65% of India's electricity generation capacity comes from thermal power plants, with about 85% of the country's thermal power generation being coal-based.
[14] The mass number of a nucleus is –
A.
always less than its atomic number
B.
always more than its atomic number
C.
always equal to its atomic number
D.
sometimes more - and somtimes equal to its atomic number
Ans:
sometimes more - and somtimes equal to its atomic number
Explanation :
Mass number = protons or mass of electron (atomic number) + neutrons. So it is mostly greater than the atomic number. At best, it can be equal to the atomic number.
[15] Ionisation energy of nitrogen is greater than that of oxygen because nitrogen has –
A.
high bond dissociation energy
B.
smaller atomic radius
C.
stable half filled 2p sub level
D.
high nuclear charge
Ans:
stable half filled 2p sub level
Explanation :
Ionization energy is a measure of the ease in which atoms lose electrons and become positive ions.
[16] Graphite is used in nuclear reactors for-
A.
reducing the speed of fast neutrons
B.
cooling the reactor
C.
absorbing neutrons
D.
None of the above
Ans:
reducing the speed of fast neutrons
Explanation :
A graphite reactor is a nuclear reactor that uses carbon as a neutron moderator, which allows un- enriched uranium to be used as nuclear fuel.
[17] Bleaching powder is prepared by passing –
A.
Chlorine over slaked lime
B.
Oxygen over slaked lime
C.
Carbon dioxide over slaked lime
D.
Chlorine over quick lirne
Ans:
Chlorine over slaked lime
Explanation :
Calcium hypochlorite (bleaching powder) is manufactured by the calcium process: 2Cl2 + 2Ca(OH)2 (slaked lime) Ca(OCl)2 + CaCl2 + 2H2O. Bleaching powder is actually a mixture of calcium hypochlorite and the basic chloride with some slaked lime.
[18] Acid rain is caused due to pollution of atmosphere by –
A.
oxides of carbon and nitrogen
B.
oxides of nitrogen and sulphur
C.
oxides of nitrogen and phosphorus
D.
None of these
Ans:
oxides of nitrogen and sulphur
Explanation :
Acid rain is caused by emissions of Sulpfur Dioxide (SO2) and Nitrogen Oxide (NOx), which react with the water molecules in the atmosphere to produce acids.
[19] The working of a dry cell is based on -
A.
Decomposition reaction
B.
Spontaneous oxidation-reduction reaction
C.
Combination reaction.
D.
Electrolysis
Ans:
Electrolysis
Explanation :
A dry cell is a type of battery that uses a paste electrolyte, with only enough moisture to allow current to flow. It works in accordance with Faraday's law of electrolysis. It consists of an outer case made of zinc the negative electrode), a carbon rod in the center of the cell (the positive electrode), and the space between them is filled with an electrolyte paste.
[20] Which of the following is the correct sequence of countries in terms of maximum carbon dioxide emission?
A.
China, USA, European Union, India
B.
USA, India, China, European Union
C.
China, India, European Union, USA
D.
European Union, China, USA, India
Ans:
China, USA, European Union, India
Explanation :
According to the EDGAR database released by European Commission and Netherlands Environmental Assessment Agency in 2014, China, USA, European Union, India and Russia are the largest emitters of carbon emission (annual CO2 emissions estimates in thousands of CO3 tonnes) across the globe.
[21] Potassium Permanganate is used for purifying drinking water, because .
A.
It is a reducing agent
B.
It is an oxidising agent
C.
It is a sterilising agent
D.
It dissolves the impurities of water
Ans:
It is an oxidising agent
Explanation :
Potassium permanganate is a point-of-entry water treatment method that oxidizes dissolved iron, mancianese, and hydrogen sulfide into solid particles that are filtered out of the water. It can al so be used to control iron bacteria growth in wells. It is an oxidant, but a poor disinfectant.
[22] Oxide of sulphur present in the atmosphere are washed down by rains to cause –
A.
Depletion of fossil fuel reserves
B.
Eutrophication in lakes
C.
Lowering of pH of soil
D.
Industrial smog formation
Ans:
Depletion of fossil fuel reserves
Explanation :
The oxide of Sulphur (Sulphur Dioxide) is washed down on earth as acid rain. It makes the soil acidic by lowering its pH; this affects plants and animals adversely. Acid rain contains H+, SO42- ions which when added to the soil leaches the nutrients from the soil. Acid rain renders the river or even ocean water acidic, thereby affecting marine animals adversely. Changes in pH of fresh water affect the reproduction and survival or many species or fish.
[23] An emulsifier is an agent which –
A.
stabilises an emulsion
B.
aids the flocculation of an emulsion
C.
accelerates the dispersion
D.
homogenises an emulsion
Ans:
stabilises an emulsion
Explanation :
An emulsifier is a substance that stabilizes an emulsion by increasing its kinetic stability. One class of emulsifiers is known as "surface active substances", or surfactants. Many different emulsifiers are used in pharmacy to prepare emulsions such as creams and lotions. Common examples include emulsifying wax, cetearyl alcohol, polysorbate 20, and ceteareth 20. Sometimes the inner phase itself can act as an emulsifier, and the result is a nanoemulsion, where the inner state disperses into "nano-size" droplets within the outer phase.
[24] Hydrogen is not found in atmosphere because –
A.
it is highly inflammable
B.
it is the lightest gas
C.
it is absorbed by plants
D.
it immediately combines with oxygen to form water
Ans:
it is the lightest gas
Explanation :
Hydrogen is a chemical element with symbol H and atomic number 1. With an average atomic weight of 1.00794 u (1.007825 u for hydrogen-1), hydrogen is the lightest element and its monatomic form (H 1) is the most abundant chemical substance, constituting roughly 75% of the Universe's baryonic mass. Non-remnant stars are mainly composed of hydrogen in its plasma state. Air is the name given to the atmosphere used in breathing and photosynthesis.
[25] The mass number of a nucleus is -
A.
always less than its atomic number
B.
the sum of the number of protons and neutrons present in the nucleus
C.
always more than the atomic weight
D.
a fraction
Ans:
the sum of the number of protons and neutrons present in the nucleus
Explanation :
Mass number = protons or mass of electron (atomic number) + neutrons. So it is mostly greater than the atomic number. At best, it can be equal to the atomic number.
Explanation :
The molecular weight (molar mass) of any gas is the mass of one particle of that gas multiplie d by Avogadro's number. It is twice its vapor pressure since the molecular mass of any gas is twice its density in relation to hydrogen which has 2 atoms in one molecule.
[12] Carbon footprint can be reduced by –
A.
All of these
B.
Recycling waste materials
C.
Using energy efficient appliances
D.
Commuting by public transport
Ans:
All of these
Explanation :
A carbon footprint is historically defined as "the total sets of greenhouse gas emissions caused by an organization, event, product or person." The most common way to reduce the carbon footprint of humans is to Reduce, Reuse, Recycle, Refuse. Recycling waste materials, using energy efficient appliances and using public transportation for commutation can all serve to reduce greenhouse gas emissions and, thus, reduce Carbon footprint.
[13] Thermal electricity is generated by using which of these?
A.
Coal only
B.
Coal and Natural Gas only
C.
Coal, Natural Gas and Petroleum
D.
None of these
Ans:
Coal, Natural Gas and Petroleum
Explanation :
A thermal power station is a power plant in which heat energy is converted to electric power. Thermal power is producing using fossil fuel such as coal, natural gas or petroleum. More than 65% of India's electricity generation capacity comes from thermal power plants, with about 85% of the country's thermal power generation being coal-based.
[14] The mass number of a nucleus is –
A.
always less than its atomic number
B.
always more than its atomic number
C.
always equal to its atomic number
D.
sometimes more - and somtimes equal to its atomic number
Ans:
sometimes more - and somtimes equal to its atomic number
Explanation :
Mass number = protons or mass of electron (atomic number) + neutrons. So it is mostly greater than the atomic number. At best, it can be equal to the atomic number.
[15] Ionisation energy of nitrogen is greater than that of oxygen because nitrogen has –
A.
high bond dissociation energy
B.
smaller atomic radius
C.
stable half filled 2p sub level
D.
high nuclear charge
Ans:
stable half filled 2p sub level
Explanation :
Ionization energy is a measure of the ease in which atoms lose electrons and become positive ions.
[16] Graphite is used in nuclear reactors for-
A.
reducing the speed of fast neutrons
B.
cooling the reactor
C.
absorbing neutrons
D.
None of the above
Ans:
reducing the speed of fast neutrons
Explanation :
A graphite reactor is a nuclear reactor that uses carbon as a neutron moderator, which allows un- enriched uranium to be used as nuclear fuel.
[17] Bleaching powder is prepared by passing –
A.
Chlorine over slaked lime
B.
Oxygen over slaked lime
C.
Carbon dioxide over slaked lime
D.
Chlorine over quick lirne
Ans:
Chlorine over slaked lime
Explanation :
Calcium hypochlorite (bleaching powder) is manufactured by the calcium process: 2Cl2 + 2Ca(OH)2 (slaked lime) Ca(OCl)2 + CaCl2 + 2H2O. Bleaching powder is actually a mixture of calcium hypochlorite and the basic chloride with some slaked lime.
[18] Acid rain is caused due to pollution of atmosphere by –
A.
oxides of carbon and nitrogen
B.
oxides of nitrogen and sulphur
C.
oxides of nitrogen and phosphorus
D.
None of these
Ans:
oxides of nitrogen and sulphur
Explanation :
Acid rain is caused by emissions of Sulpfur Dioxide (SO2) and Nitrogen Oxide (NOx), which react with the water molecules in the atmosphere to produce acids.
[19] The working of a dry cell is based on -
A.
Decomposition reaction
B.
Spontaneous oxidation-reduction reaction
C.
Combination reaction.
D.
Electrolysis
Ans:
Electrolysis
Explanation :
A dry cell is a type of battery that uses a paste electrolyte, with only enough moisture to allow current to flow. It works in accordance with Faraday's law of electrolysis. It consists of an outer case made of zinc the negative electrode), a carbon rod in the center of the cell (the positive electrode), and the space between them is filled with an electrolyte paste.
[20] Which of the following is the correct sequence of countries in terms of maximum carbon dioxide emission?
A.
China, USA, European Union, India
B.
USA, India, China, European Union
C.
China, India, European Union, USA
D.
European Union, China, USA, India
Ans:
China, USA, European Union, India
Explanation :
According to the EDGAR database released by European Commission and Netherlands Environmental Assessment Agency in 2014, China, USA, European Union, India and Russia are the largest emitters of carbon emission (annual CO2 emissions estimates in thousands of CO3 tonnes) across the globe.
[21] Potassium Permanganate is used for purifying drinking water, because .
A.
It is a reducing agent
B.
It is an oxidising agent
C.
It is a sterilising agent
D.
It dissolves the impurities of water
Ans:
It is an oxidising agent
Explanation :
Potassium permanganate is a point-of-entry water treatment method that oxidizes dissolved iron, mancianese, and hydrogen sulfide into solid particles that are filtered out of the water. It can al so be used to control iron bacteria growth in wells. It is an oxidant, but a poor disinfectant.
[22] Oxide of sulphur present in the atmosphere are washed down by rains to cause –
A.
Depletion of fossil fuel reserves
B.
Eutrophication in lakes
C.
Lowering of pH of soil
D.
Industrial smog formation
Ans:
Depletion of fossil fuel reserves
Explanation :
The oxide of Sulphur (Sulphur Dioxide) is washed down on earth as acid rain. It makes the soil acidic by lowering its pH; this affects plants and animals adversely. Acid rain contains H+, SO42- ions which when added to the soil leaches the nutrients from the soil. Acid rain renders the river or even ocean water acidic, thereby affecting marine animals adversely. Changes in pH of fresh water affect the reproduction and survival or many species or fish.
[23] An emulsifier is an agent which –
A.
stabilises an emulsion
B.
aids the flocculation of an emulsion
C.
accelerates the dispersion
D.
homogenises an emulsion
Ans:
stabilises an emulsion
Explanation :
An emulsifier is a substance that stabilizes an emulsion by increasing its kinetic stability. One class of emulsifiers is known as "surface active substances", or surfactants. Many different emulsifiers are used in pharmacy to prepare emulsions such as creams and lotions. Common examples include emulsifying wax, cetearyl alcohol, polysorbate 20, and ceteareth 20. Sometimes the inner phase itself can act as an emulsifier, and the result is a nanoemulsion, where the inner state disperses into "nano-size" droplets within the outer phase.
[24] Hydrogen is not found in atmosphere because –
A.
it is highly inflammable
B.
it is the lightest gas
C.
it is absorbed by plants
D.
it immediately combines with oxygen to form water
Ans:
it is the lightest gas
Explanation :
Hydrogen is a chemical element with symbol H and atomic number 1. With an average atomic weight of 1.00794 u (1.007825 u for hydrogen-1), hydrogen is the lightest element and its monatomic form (H 1) is the most abundant chemical substance, constituting roughly 75% of the Universe's baryonic mass. Non-remnant stars are mainly composed of hydrogen in its plasma state. Air is the name given to the atmosphere used in breathing and photosynthesis.
[25] The mass number of a nucleus is -
A.
always less than its atomic number
B.
the sum of the number of protons and neutrons present in the nucleus
C.
always more than the atomic weight
D.
a fraction
Ans:
the sum of the number of protons and neutrons present in the nucleus
Explanation :
Mass number = protons or mass of electron (atomic number) + neutrons. So it is mostly greater than the atomic number. At best, it can be equal to the atomic number.
Explanation :
A thermal power station is a power plant in which heat energy is converted to electric power. Thermal power is producing using fossil fuel such as coal, natural gas or petroleum. More than 65% of India's electricity generation capacity comes from thermal power plants, with about 85% of the country's thermal power generation being coal-based.
[14] The mass number of a nucleus is –
A.
always less than its atomic number
B.
always more than its atomic number
C.
always equal to its atomic number
D.
sometimes more - and somtimes equal to its atomic number
Ans:
sometimes more - and somtimes equal to its atomic number
Explanation :
Mass number = protons or mass of electron (atomic number) + neutrons. So it is mostly greater than the atomic number. At best, it can be equal to the atomic number.
[15] Ionisation energy of nitrogen is greater than that of oxygen because nitrogen has –
A.
high bond dissociation energy
B.
smaller atomic radius
C.
stable half filled 2p sub level
D.
high nuclear charge
Ans:
stable half filled 2p sub level
Explanation :
Ionization energy is a measure of the ease in which atoms lose electrons and become positive ions.
[16] Graphite is used in nuclear reactors for-
A.
reducing the speed of fast neutrons
B.
cooling the reactor
C.
absorbing neutrons
D.
None of the above
Ans:
reducing the speed of fast neutrons
Explanation :
A graphite reactor is a nuclear reactor that uses carbon as a neutron moderator, which allows un- enriched uranium to be used as nuclear fuel.
[17] Bleaching powder is prepared by passing –
A.
Chlorine over slaked lime
B.
Oxygen over slaked lime
C.
Carbon dioxide over slaked lime
D.
Chlorine over quick lirne
Ans:
Chlorine over slaked lime
Explanation :
Calcium hypochlorite (bleaching powder) is manufactured by the calcium process: 2Cl2 + 2Ca(OH)2 (slaked lime) Ca(OCl)2 + CaCl2 + 2H2O. Bleaching powder is actually a mixture of calcium hypochlorite and the basic chloride with some slaked lime.
[18] Acid rain is caused due to pollution of atmosphere by –
A.
oxides of carbon and nitrogen
B.
oxides of nitrogen and sulphur
C.
oxides of nitrogen and phosphorus
D.
None of these
Ans:
oxides of nitrogen and sulphur
Explanation :
Acid rain is caused by emissions of Sulpfur Dioxide (SO2) and Nitrogen Oxide (NOx), which react with the water molecules in the atmosphere to produce acids.
[19] The working of a dry cell is based on -
A.
Decomposition reaction
B.
Spontaneous oxidation-reduction reaction
C.
Combination reaction.
D.
Electrolysis
Ans:
Electrolysis
Explanation :
A dry cell is a type of battery that uses a paste electrolyte, with only enough moisture to allow current to flow. It works in accordance with Faraday's law of electrolysis. It consists of an outer case made of zinc the negative electrode), a carbon rod in the center of the cell (the positive electrode), and the space between them is filled with an electrolyte paste.
[20] Which of the following is the correct sequence of countries in terms of maximum carbon dioxide emission?
A.
China, USA, European Union, India
B.
USA, India, China, European Union
C.
China, India, European Union, USA
D.
European Union, China, USA, India
Ans:
China, USA, European Union, India
Explanation :
According to the EDGAR database released by European Commission and Netherlands Environmental Assessment Agency in 2014, China, USA, European Union, India and Russia are the largest emitters of carbon emission (annual CO2 emissions estimates in thousands of CO3 tonnes) across the globe.
[21] Potassium Permanganate is used for purifying drinking water, because .
A.
It is a reducing agent
B.
It is an oxidising agent
C.
It is a sterilising agent
D.
It dissolves the impurities of water
Ans:
It is an oxidising agent
Explanation :
Potassium permanganate is a point-of-entry water treatment method that oxidizes dissolved iron, mancianese, and hydrogen sulfide into solid particles that are filtered out of the water. It can al so be used to control iron bacteria growth in wells. It is an oxidant, but a poor disinfectant.
[22] Oxide of sulphur present in the atmosphere are washed down by rains to cause –
A.
Depletion of fossil fuel reserves
B.
Eutrophication in lakes
C.
Lowering of pH of soil
D.
Industrial smog formation
Ans:
Depletion of fossil fuel reserves
Explanation :
The oxide of Sulphur (Sulphur Dioxide) is washed down on earth as acid rain. It makes the soil acidic by lowering its pH; this affects plants and animals adversely. Acid rain contains H+, SO42- ions which when added to the soil leaches the nutrients from the soil. Acid rain renders the river or even ocean water acidic, thereby affecting marine animals adversely. Changes in pH of fresh water affect the reproduction and survival or many species or fish.
[23] An emulsifier is an agent which –
A.
stabilises an emulsion
B.
aids the flocculation of an emulsion
C.
accelerates the dispersion
D.
homogenises an emulsion
Ans:
stabilises an emulsion
Explanation :
An emulsifier is a substance that stabilizes an emulsion by increasing its kinetic stability. One class of emulsifiers is known as "surface active substances", or surfactants. Many different emulsifiers are used in pharmacy to prepare emulsions such as creams and lotions. Common examples include emulsifying wax, cetearyl alcohol, polysorbate 20, and ceteareth 20. Sometimes the inner phase itself can act as an emulsifier, and the result is a nanoemulsion, where the inner state disperses into "nano-size" droplets within the outer phase.
[24] Hydrogen is not found in atmosphere because –
A.
it is highly inflammable
B.
it is the lightest gas
C.
it is absorbed by plants
D.
it immediately combines with oxygen to form water
Ans:
it is the lightest gas
Explanation :
Hydrogen is a chemical element with symbol H and atomic number 1. With an average atomic weight of 1.00794 u (1.007825 u for hydrogen-1), hydrogen is the lightest element and its monatomic form (H 1) is the most abundant chemical substance, constituting roughly 75% of the Universe's baryonic mass. Non-remnant stars are mainly composed of hydrogen in its plasma state. Air is the name given to the atmosphere used in breathing and photosynthesis.
[25] The mass number of a nucleus is -
A.
always less than its atomic number
B.
the sum of the number of protons and neutrons present in the nucleus
C.
always more than the atomic weight
D.
a fraction
Ans:
the sum of the number of protons and neutrons present in the nucleus
Explanation :
Mass number = protons or mass of electron (atomic number) + neutrons. So it is mostly greater than the atomic number. At best, it can be equal to the atomic number.
Explanation :
Ionization energy is a measure of the ease in which atoms lose electrons and become positive ions.
[16] Graphite is used in nuclear reactors for-
A.
reducing the speed of fast neutrons
B.
cooling the reactor
C.
absorbing neutrons
D.
None of the above
Ans:
reducing the speed of fast neutrons
Explanation :
A graphite reactor is a nuclear reactor that uses carbon as a neutron moderator, which allows un- enriched uranium to be used as nuclear fuel.
[17] Bleaching powder is prepared by passing –
A.
Chlorine over slaked lime
B.
Oxygen over slaked lime
C.
Carbon dioxide over slaked lime
D.
Chlorine over quick lirne
Ans:
Chlorine over slaked lime
Explanation :
Calcium hypochlorite (bleaching powder) is manufactured by the calcium process: 2Cl2 + 2Ca(OH)2 (slaked lime) Ca(OCl)2 + CaCl2 + 2H2O. Bleaching powder is actually a mixture of calcium hypochlorite and the basic chloride with some slaked lime.
[18] Acid rain is caused due to pollution of atmosphere by –
A.
oxides of carbon and nitrogen
B.
oxides of nitrogen and sulphur
C.
oxides of nitrogen and phosphorus
D.
None of these
Ans:
oxides of nitrogen and sulphur
Explanation :
Acid rain is caused by emissions of Sulpfur Dioxide (SO2) and Nitrogen Oxide (NOx), which react with the water molecules in the atmosphere to produce acids.
[19] The working of a dry cell is based on -
A.
Decomposition reaction
B.
Spontaneous oxidation-reduction reaction
C.
Combination reaction.
D.
Electrolysis
Ans:
Electrolysis
Explanation :
A dry cell is a type of battery that uses a paste electrolyte, with only enough moisture to allow current to flow. It works in accordance with Faraday's law of electrolysis. It consists of an outer case made of zinc the negative electrode), a carbon rod in the center of the cell (the positive electrode), and the space between them is filled with an electrolyte paste.
[20] Which of the following is the correct sequence of countries in terms of maximum carbon dioxide emission?
A.
China, USA, European Union, India
B.
USA, India, China, European Union
C.
China, India, European Union, USA
D.
European Union, China, USA, India
Ans:
China, USA, European Union, India
Explanation :
According to the EDGAR database released by European Commission and Netherlands Environmental Assessment Agency in 2014, China, USA, European Union, India and Russia are the largest emitters of carbon emission (annual CO2 emissions estimates in thousands of CO3 tonnes) across the globe.
[21] Potassium Permanganate is used for purifying drinking water, because .
A.
It is a reducing agent
B.
It is an oxidising agent
C.
It is a sterilising agent
D.
It dissolves the impurities of water
Ans:
It is an oxidising agent
Explanation :
Potassium permanganate is a point-of-entry water treatment method that oxidizes dissolved iron, mancianese, and hydrogen sulfide into solid particles that are filtered out of the water. It can al so be used to control iron bacteria growth in wells. It is an oxidant, but a poor disinfectant.
[22] Oxide of sulphur present in the atmosphere are washed down by rains to cause –
A.
Depletion of fossil fuel reserves
B.
Eutrophication in lakes
C.
Lowering of pH of soil
D.
Industrial smog formation
Ans:
Depletion of fossil fuel reserves
Explanation :
The oxide of Sulphur (Sulphur Dioxide) is washed down on earth as acid rain. It makes the soil acidic by lowering its pH; this affects plants and animals adversely. Acid rain contains H+, SO42- ions which when added to the soil leaches the nutrients from the soil. Acid rain renders the river or even ocean water acidic, thereby affecting marine animals adversely. Changes in pH of fresh water affect the reproduction and survival or many species or fish.
[23] An emulsifier is an agent which –
A.
stabilises an emulsion
B.
aids the flocculation of an emulsion
C.
accelerates the dispersion
D.
homogenises an emulsion
Ans:
stabilises an emulsion
Explanation :
An emulsifier is a substance that stabilizes an emulsion by increasing its kinetic stability. One class of emulsifiers is known as "surface active substances", or surfactants. Many different emulsifiers are used in pharmacy to prepare emulsions such as creams and lotions. Common examples include emulsifying wax, cetearyl alcohol, polysorbate 20, and ceteareth 20. Sometimes the inner phase itself can act as an emulsifier, and the result is a nanoemulsion, where the inner state disperses into "nano-size" droplets within the outer phase.
[24] Hydrogen is not found in atmosphere because –
A.
it is highly inflammable
B.
it is the lightest gas
C.
it is absorbed by plants
D.
it immediately combines with oxygen to form water
Ans:
it is the lightest gas
Explanation :
Hydrogen is a chemical element with symbol H and atomic number 1. With an average atomic weight of 1.00794 u (1.007825 u for hydrogen-1), hydrogen is the lightest element and its monatomic form (H 1) is the most abundant chemical substance, constituting roughly 75% of the Universe's baryonic mass. Non-remnant stars are mainly composed of hydrogen in its plasma state. Air is the name given to the atmosphere used in breathing and photosynthesis.
[25] The mass number of a nucleus is -
A.
always less than its atomic number
B.
the sum of the number of protons and neutrons present in the nucleus
C.
always more than the atomic weight
D.
a fraction
Ans:
the sum of the number of protons and neutrons present in the nucleus
Explanation :
Mass number = protons or mass of electron (atomic number) + neutrons. So it is mostly greater than the atomic number. At best, it can be equal to the atomic number.
Explanation :
Calcium hypochlorite (bleaching powder) is manufactured by the calcium process: 2Cl2 + 2Ca(OH)2 (slaked lime) Ca(OCl)2 + CaCl2 + 2H2O. Bleaching powder is actually a mixture of calcium hypochlorite and the basic chloride with some slaked lime.
[18] Acid rain is caused due to pollution of atmosphere by –
A.
oxides of carbon and nitrogen
B.
oxides of nitrogen and sulphur
C.
oxides of nitrogen and phosphorus
D.
None of these
Ans:
oxides of nitrogen and sulphur
Explanation :
Acid rain is caused by emissions of Sulpfur Dioxide (SO2) and Nitrogen Oxide (NOx), which react with the water molecules in the atmosphere to produce acids.
[19] The working of a dry cell is based on -
A.
Decomposition reaction
B.
Spontaneous oxidation-reduction reaction
C.
Combination reaction.
D.
Electrolysis
Ans:
Electrolysis
Explanation :
A dry cell is a type of battery that uses a paste electrolyte, with only enough moisture to allow current to flow. It works in accordance with Faraday's law of electrolysis. It consists of an outer case made of zinc the negative electrode), a carbon rod in the center of the cell (the positive electrode), and the space between them is filled with an electrolyte paste.
[20] Which of the following is the correct sequence of countries in terms of maximum carbon dioxide emission?
A.
China, USA, European Union, India
B.
USA, India, China, European Union
C.
China, India, European Union, USA
D.
European Union, China, USA, India
Ans:
China, USA, European Union, India
Explanation :
According to the EDGAR database released by European Commission and Netherlands Environmental Assessment Agency in 2014, China, USA, European Union, India and Russia are the largest emitters of carbon emission (annual CO2 emissions estimates in thousands of CO3 tonnes) across the globe.
[21] Potassium Permanganate is used for purifying drinking water, because .
A.
It is a reducing agent
B.
It is an oxidising agent
C.
It is a sterilising agent
D.
It dissolves the impurities of water
Ans:
It is an oxidising agent
Explanation :
Potassium permanganate is a point-of-entry water treatment method that oxidizes dissolved iron, mancianese, and hydrogen sulfide into solid particles that are filtered out of the water. It can al so be used to control iron bacteria growth in wells. It is an oxidant, but a poor disinfectant.
[22] Oxide of sulphur present in the atmosphere are washed down by rains to cause –
A.
Depletion of fossil fuel reserves
B.
Eutrophication in lakes
C.
Lowering of pH of soil
D.
Industrial smog formation
Ans:
Depletion of fossil fuel reserves
Explanation :
The oxide of Sulphur (Sulphur Dioxide) is washed down on earth as acid rain. It makes the soil acidic by lowering its pH; this affects plants and animals adversely. Acid rain contains H+, SO42- ions which when added to the soil leaches the nutrients from the soil. Acid rain renders the river or even ocean water acidic, thereby affecting marine animals adversely. Changes in pH of fresh water affect the reproduction and survival or many species or fish.
[23] An emulsifier is an agent which –
A.
stabilises an emulsion
B.
aids the flocculation of an emulsion
C.
accelerates the dispersion
D.
homogenises an emulsion
Ans:
stabilises an emulsion
Explanation :
An emulsifier is a substance that stabilizes an emulsion by increasing its kinetic stability. One class of emulsifiers is known as "surface active substances", or surfactants. Many different emulsifiers are used in pharmacy to prepare emulsions such as creams and lotions. Common examples include emulsifying wax, cetearyl alcohol, polysorbate 20, and ceteareth 20. Sometimes the inner phase itself can act as an emulsifier, and the result is a nanoemulsion, where the inner state disperses into "nano-size" droplets within the outer phase.
[24] Hydrogen is not found in atmosphere because –
A.
it is highly inflammable
B.
it is the lightest gas
C.
it is absorbed by plants
D.
it immediately combines with oxygen to form water
Ans:
it is the lightest gas
Explanation :
Hydrogen is a chemical element with symbol H and atomic number 1. With an average atomic weight of 1.00794 u (1.007825 u for hydrogen-1), hydrogen is the lightest element and its monatomic form (H 1) is the most abundant chemical substance, constituting roughly 75% of the Universe's baryonic mass. Non-remnant stars are mainly composed of hydrogen in its plasma state. Air is the name given to the atmosphere used in breathing and photosynthesis.
[25] The mass number of a nucleus is -
A.
always less than its atomic number
B.
the sum of the number of protons and neutrons present in the nucleus
C.
always more than the atomic weight
D.
a fraction
Ans:
the sum of the number of protons and neutrons present in the nucleus
Explanation :
Mass number = protons or mass of electron (atomic number) + neutrons. So it is mostly greater than the atomic number. At best, it can be equal to the atomic number.
Explanation :
A dry cell is a type of battery that uses a paste electrolyte, with only enough moisture to allow current to flow. It works in accordance with Faraday's law of electrolysis. It consists of an outer case made of zinc the negative electrode), a carbon rod in the center of the cell (the positive electrode), and the space between them is filled with an electrolyte paste.
[20] Which of the following is the correct sequence of countries in terms of maximum carbon dioxide emission?
A.
China, USA, European Union, India
B.
USA, India, China, European Union
C.
China, India, European Union, USA
D.
European Union, China, USA, India
Ans:
China, USA, European Union, India
Explanation :
According to the EDGAR database released by European Commission and Netherlands Environmental Assessment Agency in 2014, China, USA, European Union, India and Russia are the largest emitters of carbon emission (annual CO2 emissions estimates in thousands of CO3 tonnes) across the globe.
[21] Potassium Permanganate is used for purifying drinking water, because .
A.
It is a reducing agent
B.
It is an oxidising agent
C.
It is a sterilising agent
D.
It dissolves the impurities of water
Ans:
It is an oxidising agent
Explanation :
Potassium permanganate is a point-of-entry water treatment method that oxidizes dissolved iron, mancianese, and hydrogen sulfide into solid particles that are filtered out of the water. It can al so be used to control iron bacteria growth in wells. It is an oxidant, but a poor disinfectant.
[22] Oxide of sulphur present in the atmosphere are washed down by rains to cause –
A.
Depletion of fossil fuel reserves
B.
Eutrophication in lakes
C.
Lowering of pH of soil
D.
Industrial smog formation
Ans:
Depletion of fossil fuel reserves
Explanation :
The oxide of Sulphur (Sulphur Dioxide) is washed down on earth as acid rain. It makes the soil acidic by lowering its pH; this affects plants and animals adversely. Acid rain contains H+, SO42- ions which when added to the soil leaches the nutrients from the soil. Acid rain renders the river or even ocean water acidic, thereby affecting marine animals adversely. Changes in pH of fresh water affect the reproduction and survival or many species or fish.
[23] An emulsifier is an agent which –
A.
stabilises an emulsion
B.
aids the flocculation of an emulsion
C.
accelerates the dispersion
D.
homogenises an emulsion
Ans:
stabilises an emulsion
Explanation :
An emulsifier is a substance that stabilizes an emulsion by increasing its kinetic stability. One class of emulsifiers is known as "surface active substances", or surfactants. Many different emulsifiers are used in pharmacy to prepare emulsions such as creams and lotions. Common examples include emulsifying wax, cetearyl alcohol, polysorbate 20, and ceteareth 20. Sometimes the inner phase itself can act as an emulsifier, and the result is a nanoemulsion, where the inner state disperses into "nano-size" droplets within the outer phase.
[24] Hydrogen is not found in atmosphere because –
A.
it is highly inflammable
B.
it is the lightest gas
C.
it is absorbed by plants
D.
it immediately combines with oxygen to form water
Ans:
it is the lightest gas
Explanation :
Hydrogen is a chemical element with symbol H and atomic number 1. With an average atomic weight of 1.00794 u (1.007825 u for hydrogen-1), hydrogen is the lightest element and its monatomic form (H 1) is the most abundant chemical substance, constituting roughly 75% of the Universe's baryonic mass. Non-remnant stars are mainly composed of hydrogen in its plasma state. Air is the name given to the atmosphere used in breathing and photosynthesis.
[25] The mass number of a nucleus is -
A.
always less than its atomic number
B.
the sum of the number of protons and neutrons present in the nucleus
C.
always more than the atomic weight
D.
a fraction
Ans:
the sum of the number of protons and neutrons present in the nucleus
Explanation :
Mass number = protons or mass of electron (atomic number) + neutrons. So it is mostly greater than the atomic number. At best, it can be equal to the atomic number.
Explanation :
Potassium permanganate is a point-of-entry water treatment method that oxidizes dissolved iron, mancianese, and hydrogen sulfide into solid particles that are filtered out of the water. It can al so be used to control iron bacteria growth in wells. It is an oxidant, but a poor disinfectant.
[22] Oxide of sulphur present in the atmosphere are washed down by rains to cause –
A.
Depletion of fossil fuel reserves
B.
Eutrophication in lakes
C.
Lowering of pH of soil
D.
Industrial smog formation
Ans:
Depletion of fossil fuel reserves
Explanation :
The oxide of Sulphur (Sulphur Dioxide) is washed down on earth as acid rain. It makes the soil acidic by lowering its pH; this affects plants and animals adversely. Acid rain contains H+, SO42- ions which when added to the soil leaches the nutrients from the soil. Acid rain renders the river or even ocean water acidic, thereby affecting marine animals adversely. Changes in pH of fresh water affect the reproduction and survival or many species or fish.
[23] An emulsifier is an agent which –
A.
stabilises an emulsion
B.
aids the flocculation of an emulsion
C.
accelerates the dispersion
D.
homogenises an emulsion
Ans:
stabilises an emulsion
Explanation :
An emulsifier is a substance that stabilizes an emulsion by increasing its kinetic stability. One class of emulsifiers is known as "surface active substances", or surfactants. Many different emulsifiers are used in pharmacy to prepare emulsions such as creams and lotions. Common examples include emulsifying wax, cetearyl alcohol, polysorbate 20, and ceteareth 20. Sometimes the inner phase itself can act as an emulsifier, and the result is a nanoemulsion, where the inner state disperses into "nano-size" droplets within the outer phase.
[24] Hydrogen is not found in atmosphere because –
A.
it is highly inflammable
B.
it is the lightest gas
C.
it is absorbed by plants
D.
it immediately combines with oxygen to form water
Ans:
it is the lightest gas
Explanation :
Hydrogen is a chemical element with symbol H and atomic number 1. With an average atomic weight of 1.00794 u (1.007825 u for hydrogen-1), hydrogen is the lightest element and its monatomic form (H 1) is the most abundant chemical substance, constituting roughly 75% of the Universe's baryonic mass. Non-remnant stars are mainly composed of hydrogen in its plasma state. Air is the name given to the atmosphere used in breathing and photosynthesis.
[25] The mass number of a nucleus is -
A.
always less than its atomic number
B.
the sum of the number of protons and neutrons present in the nucleus
C.
always more than the atomic weight
D.
a fraction
Ans:
the sum of the number of protons and neutrons present in the nucleus
Explanation :
Mass number = protons or mass of electron (atomic number) + neutrons. So it is mostly greater than the atomic number. At best, it can be equal to the atomic number.
Explanation :
An emulsifier is a substance that stabilizes an emulsion by increasing its kinetic stability. One class of emulsifiers is known as "surface active substances", or surfactants. Many different emulsifiers are used in pharmacy to prepare emulsions such as creams and lotions. Common examples include emulsifying wax, cetearyl alcohol, polysorbate 20, and ceteareth 20. Sometimes the inner phase itself can act as an emulsifier, and the result is a nanoemulsion, where the inner state disperses into "nano-size" droplets within the outer phase.
[24] Hydrogen is not found in atmosphere because –
A.
it is highly inflammable
B.
it is the lightest gas
C.
it is absorbed by plants
D.
it immediately combines with oxygen to form water
Ans:
it is the lightest gas
Explanation :
Hydrogen is a chemical element with symbol H and atomic number 1. With an average atomic weight of 1.00794 u (1.007825 u for hydrogen-1), hydrogen is the lightest element and its monatomic form (H 1) is the most abundant chemical substance, constituting roughly 75% of the Universe's baryonic mass. Non-remnant stars are mainly composed of hydrogen in its plasma state. Air is the name given to the atmosphere used in breathing and photosynthesis.
[25] The mass number of a nucleus is -
A.
always less than its atomic number
B.
the sum of the number of protons and neutrons present in the nucleus
C.
always more than the atomic weight
D.
a fraction
Ans:
the sum of the number of protons and neutrons present in the nucleus
Explanation :
Mass number = protons or mass of electron (atomic number) + neutrons. So it is mostly greater than the atomic number. At best, it can be equal to the atomic number.
Explanation :
Mass number = protons or mass of electron (atomic number) + neutrons. So it is mostly greater than the atomic number. At best, it can be equal to the atomic number.