Class 11 Chemistry MCQ Chapter 14 Environmental Chemistry
Welcome to Class 11 Chemistry MCQ Chapter 14 Environmental Chemistry English Medium. If you are an AHSEC Higher Secondary First Year student looking for important MCQ questions and answers, this article will help you prepare effectively for your examinations.
The chapter Environmental Chemistry focuses on the study of chemical processes occurring in the environment and their impact on living organisms. Students will learn about air pollution, water pollution, soil pollution, industrial waste, greenhouse effect, global warming, ozone layer depletion, acid rain, and various methods of environmental protection. These topics are highly relevant in today’s world and are frequently asked in examinations.
The MCQs provided here are prepared according to the latest AHSEC syllabus and examination pattern. They help students revise important concepts quickly, improve their understanding of environmental issues, and become familiar with exam-oriented objective questions.
Whether you are preparing for school tests, annual examinations, or the AHSEC HS First Year Final Examination, these MCQ solutions will support your revision and help you score better marks in Chemistry.
Part II
Class 11 Chemistry MCQ Chapter 14 Environmental Chemistry
Selected VSA & MCQ
I. Very Short Answer Questions (VSA)
Q: What is environmental chemistry?
Ans: Environmental chemistry is the branch of chemistry that deals with the study of
chemical processes occurring in the environment.
Q: What is environment?
Ans: Environment is the surrounding in which living organisms interact with physical,
chemical and biological components.
Q: What is pollution?
Ans: Pollution is the undesirable change in the physical, chemical or biological
characteristics of the environment.
Q: What are pollutants?
Ans: Pollutants are substances that cause pollution.
Q: What are biodegradable pollutants?
Ans: Biodegradable pollutants are pollutants that can be decomposed by
microorganisms.
Q: What are non-biodegradable pollutants?
Ans: Non-biodegradable pollutants are pollutants that cannot be decomposed easily by
microorganisms.
Q: What is atmospheric pollution?
Ans: Atmospheric pollution is the contamination of air by harmful substances.
Q: Name the major components of air.
Ans: Nitrogen and oxygen are the major components of air.
Q: What is particulate matter?
Ans: Particulate matter consists of tiny solid or liquid particles suspended in air.
Q: What are primary pollutants?
Ans: Primary pollutants are pollutants directly emitted into the atmosphere.
Q: What are secondary pollutants?
Ans: Secondary pollutants are pollutants formed by chemical reactions in the
atmosphere.
Q: What is smog?
Ans: Smog is a mixture of smoke and fog present in the atmosphere.
Q: What is classical smog?
Ans: Classical smog is smog formed in cool and humid climate due to smoke, fog and
sulphur dioxide.
Q: What is photochemical smog?
Ans: Photochemical smog is smog formed by the action of sunlight on nitrogen oxides
and hydrocarbons.
Q: Which gas is mainly responsible for photochemical smog?
Ans: Nitrogen oxides are mainly responsible for photochemical smog.
Q: What is acid rain?
Ans: Acid rain is rain water having pH less than 5.6 due to dissolved acidic oxides.
Q: Which gases are mainly responsible for acid rain?
Ans: Sulphur dioxide and nitrogen oxides are mainly responsible for acid rain.
Q: What is greenhouse effect?
Ans: Greenhouse effect is the warming of the earth due to trapping of heat by
greenhouse gases.
Q: Name two greenhouse gases.
Ans: Carbon dioxide and methane are greenhouse gases.
Q: What is global warming?
Ans: Global warming is the gradual increase in the average temperature of the earth.
Q: What is ozone layer?
Ans: Ozone layer is the layer of ozone present in the stratosphere that protects the earth
from harmful ultraviolet rays.
Q: What causes depletion of ozone layer?
Ans: Chlorofluorocarbons (CFCs) cause depletion of ozone layer.
Q: What are chlorofluorocarbons?
Ans: Chlorofluorocarbons are compounds containing carbon, chlorine and fluorine.
Q: What is eutrophication?
Ans: Eutrophication is the excessive growth of aquatic plants due to nutrient enrichment
in water bodies.
Q: What is water pollution?
Ans: Water pollution is the contamination of water by harmful substances.
Q: Name one water pollutant.
Ans: Industrial waste is a water pollutant.
Q: What is dissolved oxygen (DO)?
Ans: Dissolved oxygen is the amount of oxygen dissolved in water.
Q: What is biochemical oxygen demand (BOD)?
Ans: Biochemical oxygen demand is the amount of oxygen required by microorganisms
to decompose organic matter in water.
Q: What does high BOD indicate?
Ans: High BOD indicates high level of organic pollution in water.
Q: What is soil pollution?
Ans: Soil pollution is the contamination of soil by harmful chemicals and wastes.
Q: Name one cause of soil pollution.
Ans: Excessive use of pesticides causes soil pollution.
Q: What are pesticides?
Ans: Pesticides are chemicals used to kill pests.
Q: What are insecticides?
Ans: Insecticides are chemicals used to kill insects.
Q: What are herbicides?
Ans: Herbicides are chemicals used to destroy weeds.
Q: What is industrial waste?
Ans: Industrial waste is waste produced from industrial activities.
Q: What is radioactive pollution?
Ans: Radioactive pollution is pollution caused by radioactive substances.
Q: What is green chemistry?
Ans: Green chemistry is the development of chemical processes that reduce or eliminate
hazardous substances.
Q: State one objective of green chemistry.
Ans: One objective of green chemistry is to reduce environmental pollution.
Q: What is the role of catalytic converters in automobiles?
Ans: Catalytic converters reduce the emission of harmful gases from automobiles.
Q: Why is CNG preferred as a fuel?
Ans: CNG is preferred because it produces less pollution.
Q: What is the full form of CFC?
Ans: The full form of CFC is chlorofluorocarbon.
II. Multiple Choice Questions (MCQs)
Q: Environmental chemistry deals with the study of —
(a) Chemical processes in industries only
(b) Chemical processes occurring in the environment
(c) Agricultural chemicals only
(d) Nuclear reactions only
Ans: (b) Chemical processes occurring in the environment
Q: Pollution is the —
(a) Purification of air
(b) Natural change in climate
(c) Undesirable change in environment
(d) Increase in soil fertility
Ans: (c) Undesirable change in environment
Q: Substances causing pollution are called —
(a) Nutrients
(b) Pollutants
(c) Catalysts
(d) Fertilisers
Ans: (b) Pollutants
Q: Biodegradable pollutants can be decomposed by —
(a) Sunlight only
(b) Water only
(c) Microorganisms
(d) Minerals
Ans: (c) Microorganisms
Q: Non-biodegradable pollutants —
(a) Decompose rapidly
(b) Cannot be decomposed easily
(c) Increase soil fertility
(d) Produce oxygen
Ans: (b) Cannot be decomposed easily
Q: The major components of air are —
(a) Carbon dioxide and methane
(b) Oxygen and hydrogen
(c) Nitrogen and oxygen
(d) Nitrogen and helium
Ans: (c) Nitrogen and oxygen
Q: Particulate matter consists of —
(a) Dissolved salts only
(b) Tiny solid or liquid particles in air
(c) Only gases
(d) Radioactive substances only
Ans: (b) Tiny solid or liquid particles in air
Q: Primary pollutants are those which are —
(a) Formed in atmosphere
(b) Directly emitted into atmosphere
(c) Produced by plants
(d) Biodegradable only
Ans: (b) Directly emitted into atmosphere
Q: Secondary pollutants are formed by —
(a) Nuclear reactions
(b) Biological reactions only
(c) Chemical reactions in atmosphere
(d) Physical reactions only
Ans: (c) Chemical reactions in atmosphere
Q: Smog is a mixture of —
(a) Smoke and fog
(b) Smoke and steam
(c) Fog and dust
(d) Oxygen and smoke
Ans: (a) Smoke and fog
Q: Photochemical smog is formed due to the action of sunlight on —
(a) Oxygen and nitrogen
(b) Nitrogen oxides and hydrocarbons
(c) Sulphur and oxygen
(d) Carbon dioxide and water vapour
Ans: (b) Nitrogen oxides and hydrocarbons
Q: Which gases are mainly responsible for acid rain?
(a) Oxygen and nitrogen
(b) Carbon monoxide and methane
(c) Sulphur dioxide and nitrogen oxides
(d) Hydrogen and chlorine
Ans: (c) Sulphur dioxide and nitrogen oxides
Q: Acid rain has pH less than —
(a) 7
(b) 6.5
(c) 5.6
(d) 4.5
Ans: (c) 5.6
Q: The greenhouse effect causes —
(a) Cooling of earth
(b) Warming of earth
(c) Formation of ozone
(d) Soil erosion
Ans: (b) Warming of earth
Q: Which of the following is a greenhouse gas?
(a) Nitrogen
(b) Oxygen
(c) Carbon dioxide
(d) Helium
Ans: (c) Carbon dioxide
Q: Global warming refers to —
(a) Cooling of atmosphere
(b) Increase in average temperature of earth
(c) Formation of acid rain
(d) Increase in rainfall only
Ans: (b) Increase in average temperature of earth
Q: The ozone layer is present in the —
(a) Troposphere
(b) Mesosphere
(c) Stratosphere
(d) Thermosphere
Ans: (c) Stratosphere
Q: Ozone layer protects the earth from —
(a) Infrared rays
(b) Visible light
(c) Ultraviolet rays
(d) Radio waves
Ans: (c) Ultraviolet rays
Q: Ozone depletion is mainly caused by —
(a) Methane
(b) Carbon dioxide
(c) Chlorofluorocarbons
(d) Nitrogen
Ans: (c) Chlorofluorocarbons
Q: CFC stands for —
(a) Carbon Fluoride Compound
(b) Chlorofluorocarbon
(c) Chemical Fuel Compound
(d) Carbon Fuel Catalyst
Ans: (b) Chlorofluorocarbon
Q: Eutrophication occurs due to excessive growth of —
(a) Animals
(b) Aquatic plants
(c) Fungi
(d) Insects
Ans: (b) Aquatic plants
Q: Water pollution is caused by —
(a) Pure water only
(b) Harmful substances in water
(c) Oxygen in water
(d) Sunlight only
Ans: (b) Harmful substances in water
Q: Dissolved oxygen (DO) refers to oxygen —
(a) Present in atmosphere
(b) Combined with hydrogen
(c) Dissolved in water
(d) Present in soil
Ans: (c) Dissolved in water
Q: BOD stands for —
(a) Biological Oxygen Development
(b) Biochemical Oxygen Demand
(c) Basic Oxygen Deficiency
(d) Biological Oxidation Difference
Ans: (b) Biochemical Oxygen Demand
Q: High BOD value indicates —
(a) Pure water
(b) Low pollution
(c) High organic pollution
(d) Absence of microorganisms
Ans: (c) High organic pollution
Q: Soil pollution is mainly caused by excessive use of —
(a) Water
(b) Fertile soil
(c) Pesticides
(d) Oxygen
Ans: (c) Pesticides
Q: Chemicals used to kill insects are called —
(a) Herbicides
(b) Fungicides
(c) Insecticides
(d) Fertilisers
Ans: (c) Insecticides
Q: Chemicals used to destroy weeds are called —
(a) Herbicides
(b) Insecticides
(c) Catalysts
(d) Pesticides
Ans: (a) Herbicides
Q: Green chemistry aims to —
(a) Increase pollution
(b) Eliminate hazardous substances
(c) Increase industrial waste
(d) Produce more smoke
Ans: (b) Eliminate hazardous substances
Q: Catalytic converters are used in automobiles to —
(a) Increase fuel consumption
(b) Reduce harmful gas emission
(c) Increase speed
(d) Produce oxygen
Ans: (b) Reduce harmful gas emission
Assertion–Reason Type MCQs
Q: Assertion (A): Acid rain damages buildings and monuments.
Reason (R): Acid rain contains sulphuric and nitric acids.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is not the correct explanation of A
(c) A is true but R is false
(d) A is false but R is true
Ans: (a) Both A and R are true and R is the correct explanation of A
Q: Assertion (A): Photochemical smog is more common in sunny climates.
Reason (R): Sunlight helps reactions of nitrogen oxides and hydrocarbons.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is not the correct explanation of A
(c) A is true but R is false
(d) A is false but R is true
Ans: (a) Both A and R are true and R is the correct explanation of A
Q: Assertion (A): Ozone layer is important for life on earth.
Reason (R): Ozone layer absorbs harmful ultraviolet radiation.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is not the correct explanation of A
(c) A is true but R is false
(d) A is false but R is true
Ans: (a) Both A and R are true and R is the correct explanation of A
Q: Assertion (A): High BOD indicates polluted water.
Reason (R): More oxygen is required to decompose organic matter in polluted water.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is not the correct explanation of A
(c) A is true but R is false
(d) A is false but R is true
Ans: (a) Both A and R are true and R is the correct explanation of A
Q: Assertion (A): Greenhouse gases increase the temperature of earth.
Reason (R): Greenhouse gases trap heat radiated from earth.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is not the correct explanation of A
(c) A is true but R is false
(d) A is false but R is true
Ans: (a) Both A and R are true and R is the correct explanation of A
Q: Assertion (A): CNG is considered a clean fuel.
Reason (R): CNG produces less pollution compared to petrol and diesel.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is not the correct explanation of A
(c) A is true but R is false
(d) A is false but R is true
Ans: (a) Both A and R are true and R is the correct explanation of A
Q: Assertion (A): Non-biodegradable pollutants remain in the environment for a long
time.
Reason (R): They cannot be decomposed easily by microorganisms.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is not the correct explanation of A
(c) A is true but R is false
(d) A is false but R is true
Ans: (a) Both A and R are true and R is the correct explanation of A. 0 0 0
