Additional Questions Solved
I. Choose the correct answer
Question 1.
Which one of the following is bio-degradable pollutant?
(a) DDT
(b) Plastics
(c) Mercury
(d) Wood
Answer:
(d) Wood
Question 2.
Which one of the following gases is not present in troposphere?
(a) N2O2
(b) CO2
(c) N2
(d) water vapours
Answer:
(c) N2
Question 3.
Which of the following pair of’ oxides is responsible for acid rain?
(a) SO3 + NO2
(b) CO2 + CO
(c) N2O + CH4
(d) O2 + H2
Answer:
(a) SO3 + NO2
Question 4.
Which one of the following is produced as a result of incomplete combustion of coal’?
(a) CO2
(b) CO
(c) SO2
(d) SO3
Answer:
(b) CO
Question 5.
Which of the following is not a greenhouse gas’?
(a) CO
(b) O3
(c) CH4
(d) Water vapours
Answer:
(a) CO
Question 6.
Photochemical smog occurs in warm, dry and sunny climate. One of the following is not among-st the components of photochemical smog. Identify it.
(a) NO2
(b) O3
(c) SO2
(d) Unsaturated hydrocarbons
Answer:
(c) SO2
II. Match the following
1.
Answer:
Answer:
Answer:
Answer:
Answer:
Answer:
III. Fill in the blanks
Question 1.
An example for biodegradable pollutant is ………
Answer:
plant waste.
Question 2.
An example for non-biodegradable pollutant ………
Answer:
metal waste.
Question 3
……… is the lowest layer of atmosphere.
Answer:
Troposphere.
Question 4.
Ozone is present in ……… layer of the atmosphere.
Answer:
Stratosphere.
Question 5
……… is called blue planet.
Answer:
Earth.
Question 6.
About 80% of the mass of the atmosphere is present in ………
Answer:
Troposphere.
Question 7.
……… will reduce the oxygen carrying capacity of blood.
Answer:
CO
Question 8
……… gas is used in the process of photosynthesis.
Answer:
CO2
Question 9.
……… gas potentially damage plant leaves and retard photosynthesis.
Answer:
NO2
Question 10.
……… is formed by incomplete combustion of coal.
Answer:
CO2
Question 11.
……… binds with haemoglobin and reduce the oxygen carrying capacity of blood.
Answer:
CO
Question 12.
……… is carcinogenic and causes irritation in eyes and mucous membrane.
Answer:
PAH
Question 13.
The earth surface get heated up by a phenomenon called ………
Answer:
Greenhouse effect
Question 14.
The main constituent of layer responsible for global warming is ………
Answer:
CO2
Question 15.
Earth’s average surface temperature would be only about ………
Answer:
-18°C
Question 16.
The pH of rain water is normally ………
Answer:
5.6
Question 17.
……… pair of compounds is present in acid-rain water.
Answer:
HNO3 + H2SO4
Question 18.
……… is an example of viable particulate.
Answer:
Bacteria.
Question 19.
……… is an example of non-viable particulate matter.
Answer:
Cement dust.
Question 20.
Particulate pollutants will result in the health hazard named as ………
Answer:
pneimoconiosis.
Question 21.
Coal miners may suffer from ………
Answer:
Black lung disease.
Question 22.
Textile workers may suifer from ………
Answer:
White lung disease.
Question 23.
………….. aftect childrcns brain. interfers with maturation of RBC’s and even causes cancer.
Answer:
Lead.
Question 24.
……… can be used to reduce particulate pollutant.
Answer:
electrostatic precipitator
Question 25.
……… is the combination of smoke and fog.
Answer:
Smog.
Question 26.
Classical smog called London smog contains ………
Answer:
Coal-smoke and fog.
Question 27.
Classical smog is otherwise called ………
Answer:
reducing smog.
Question 28.
Photochemical smog is otherwise called ………
Answer:
Los angeles smog.
Question 29.
The three main components of photochemical sinog are ………
Answer:
Hydrogen sulphide. dust and PAN.
Question 30.
……… plantation can metabolise nitrogen oxide and control photochemical smog.
Answer:
Pinus tree.
Question 31.
……… acts as an umbrella for the earth and prevent harmful UV radiations.
Answer:
ozone.
Question 32.
……… pair of compounds is found to be highly responsible for depletion of ozone layer.
Answer:
Nitric oxide + CFC
Question 33.
Freons are ………
Answer:
Chiorofluoro alkanes.
Question 34.
Ozone layer is depicted by the reactive ………
Answer:
Chlorine atom.
Question 35.
Examples for water borne diseases are ………
Answer:
Dysentery and cholera.
Question 36.
The standard pH of drinking water is ………
Answer:
6.5 to 8.5
Question 37.
The essential elements for soil are ………
Answer:
N,P,K
Question 38
……… is a better alternative for carnicogentic benzene.
Answer:
Xylene.
Question 39.
The alternate solvent used instead of tetrachioroethYlefle in dry cleaning is ………
Answer:
Liquefied CO2
Question 40.
……… is used for bleaching clothes in laundry.
Answer:
H2O2
Question 41.
……… is used to bleach paper.
Answer:
H2O2
Question 42.
……… is the most safest pesticide.
Answer:
Neem based pesticide.
Question 43.
……… acid is most abundant ¡n acid rain.
Answer:
H2SO4
Question 44.
……… causes less pollution.
Answer:
CO2
Question 45.
Besides CO2 the other greenhouse gas is ………
Answer:
CH4
Question 46.
BOD is a measure of ………
Answer:
Organic pollutant in water.
Question 47.
The pollutant released in Bhopal gas tragedy was ………
Answer:
Methyl isocyanate.
Question 48.
The greatest affinity for haemoglobin in shown by ………
Answer:
CO
Question 49.
Eutrophication causes reduction in ………
Answer:
dissolved oxygen.
IV Choose the odd one out
Question 1.
(a) Plant waste
(b) DDT
(c) Plastic
(d) Nuclear waste
Answer:
(a) Plant waste. It is biodegradable pollutant whereas others are non-biodegradable pollutants.
Question 2.
(a) Plant waste
(b) Animal wastes
(c) Paper
(d) Nuclear waste
Answer:
(d) Nuclear waste. It is non-biodegradable pollutant whereas others are biodegradable wastes.
Question 3.
(a) N2O2
(b) CO2
(c) H2O (Vap)
(d) O3
Answer:
(d) O3 It is present in stratosphere whereas others are present in troposphere.
Question 4.
(a) O2+
(b) O+
(c) N2
(d) NO+
Answer:
(c) N2. ills present in mesosphere whereas others are present in thermosphere.
Question 5.
(a) N2
(b) O2
(c) O3
(d) N2O2
Answer:
(d) N2O2 It is present in troposphere whereas others are present in stratosphere.
Question 6.
(a) CH4
(b) CO
(c) CO2
(d) CFC
Answer:
(b) CO. It is a poisonous gas whereas others are responsible for green house effect.
V. Choose the correct pair
Question 1.
(a) CCF : Green house effect
(b) CO : Carcinogenic
(c) PAH : Acid rain
(d) NO : Lung injury
Answer:
(a) CCF : Green house effect
Question 2.
(a) NO2 : Green house effect
(b) CFC : asthma and lung injury
(c) PAH : carcinogenic
(d) CO2 : green house effect
Answer:
(a) NO2 : Green house effect
Question 3.
(a) Classical smog : NO2 and O2
(b) London smog : SO2, SO2 and humidity
(c) Photochemical smog : CO2 and CO
(d) Los Angel smog : NO2 and NO3
Answer:
(b) London smog : SO2 , SO2 and humidity
VI. Choose the incorrect pair
Question 1.
(a) Photochemical smog : NO2 and O2
(b) Classical smog : SO2, SO3 and humidity
(c) Smog : Smoke and fog
(d) Non viable particulate : Algae, Fungi
Answer:
(d) Non viable particulate : Algae, Fungi
Question 2.
(a) Viable particulate : bacteria, fungi
(b) Non viable particulate : smoke, dust
(c) Acid rain : HCl + HNO2
(d) Photochemical smog : NO2 + O3
Answer:
(c) Acid rain : HCl + HNO2
Question 3.
(a) Lead : Damage to kidney, liver
(b) Sulphate : Laxative effect
(c) Nitrage : Blue baby syndrome
(d) TDS : Damage to bone and teeth
Answer:
(d) TDS : Damage to bone and teeth
Question 4.
(a) Insecticides : DDT. BCHs
(b) Herbicides : Organo mercury compounds
(c) Herbicides : Sodium chlorate, sodium arsenite
(d) Industrial waste : Mercury. copper
Answer:
(b) Herbicides : Organo mercuiy compounds
VII. Assertion & Reason
Assertion (A) : Depletion of ozone layer causes skin cancer.
Reason (R) : Depletion olozone layer will allow more UV rays to reach the earth surface and cause skin cancer.
(a) Both (A) and (R) are correct and (R)is the correct explanation of (A).
(b) Both (A) and (R) are correct but (R) is not the correct explanation of (R).
(c) (A) is correct but (R) is wrong.
(d) (A) is wrong but (R) is correct.
Answer:
(a) Both (A) and (R) are correct and (R) is the correct explanation of (A).
Question 2.
Assertion (A) : UV radiations damages the fish productivity.
Reason (R) : UV radiations affect the growth of phytoplankions as a result food chain in ocean is disturbed.
(a) Both (A) and (R) are correct hut (R) is not the correct explanation of (A).
(b) Both (A) and (R) are correct and (R) is the correct explanation of (A).
(c) (A) is correct but (R) is wrong.
(d) (A) is wrong but (R) is correct.
Answer:
(b) Both (A) and (R) are correct and (R) is the correct explanation of (A).
Question 3.
Assertion (A) : The pH ol acid rain is less than 5.6.
Reason (R) : CO, present in the atmosphere dissolves in rain water and forms carbonic acid,
(a) Both (A) and (R) are correct and (R) is the correct explanation of (A).
(b) Both (A) and (R) are correct hut (R) is not correct explanation of (A).
(c) (A) is correct bitt (R) is wrong.
(d) (A) is wrong but (R) is correct.
Answer:
(a) Both (A) and (R) are correct and (R) is the correct explanation of (A).
2 Mark Questions and Answers
Question 1.
What is meant by environmental pollution?
Answer:
Any undesirable change in our environment that have harmful effects on plants. animals and human beings is called environmental pollution.
Question 2.
Write a note on constituents of earth’s atmosphere.
Answer:
Earth’s atmosphere is a layer of gases retained by earth’s gravity. it contains roughly 78% Nitrogen, 21% Oxygen. 0.93% Argon, 0.04% Carbon dioxide. traces of other gases and little amount of water vapour. This mixture is commonly known as air.
Question 3.
What is called troposphere? How many layers are present in it? Give their names.
Answer:
· Hydrosphere
· Lithosphere
· Biosphere
Question 4.
Write about hydrosphere (or) Why Earth is called as Blue planer?
Answer:
Question 5.
What is lithosphere?
Answer:
Lithosphere includes soil, rocks and mountains which are solid components of Earth.
Question 6.
What is biosphere?
Answer:
Biosphere includes the lithosphere. hydrosphere and atmosphere integrating the living organisms present in the lithosphere, hydrosphere and atmosphere.
Question 7.
What is air pollution?
Answer:
Air pollution is defined as any undesirable change in air which adversely affects living organisms. Air pollution is limited to troposphere and stratosphere.
Question 8.
What are the types of air pollutants? Give examples.
Answer:
1. Air pollutants exists in two major forms namely:
(a) Gaseous air pollutants
(b) Particulates
2. Gaseous air pollutants:
Oxides of sulphur, oxides of nitrogen, oxides of carbon and hydrocarbons are the gaseous air pollutants.
3. Particulate pollutants:
Particulate pollutants are small solid particles and liquid droplets suspended in air.
Exarnple:
dust, pollen, smoke, soot, aerosols.
Question 9.
Define greenhouse effect.
Answer:
Greenhouse effect is defined as the heating up of the earth’s surface due to trapping of infrared radiations reflected by earth’s surface by the CO2 layer in the atmosphere.
Question 10.
What is Global warming?
Answer:
The heating up of the earth through the greenhouse effect is called Global warming.
Question 11.
When rain water is named as acid rain?
Answer:
Rain water normally has a pH of 5.6 due to dissolution of atmospheric CO2 particles into it. Oxides of sulphur and nitrogen in the atmosphere are absorbed by droplets of water that make up clouds and get chemically converted into sulphuric acid and nitric acid. As a result the pH of rainwater drops below 5.6 and hence it is called acid rain.
Question 12.
What is stone leprosy? How is it formed?
Answer:
Question 13.
What are fumes? Give one example.
Answer:
Fumes are one of the non-viable particulate pollutants air. They are obtained by condensation of vapours released during sublimation, distillation, boiling and calcination. For example, organic solvents, metals and metallic oxides form fume particles.
Question 14.
What are the techniques to reduce particulate pollutants?
Answer:
The particulates from air can be removed by using electrostatic precipitators, gravity settling chambers, wet scrubbers or by cyclone collectors. These techniques are base on washing away or settling of the particulate matter.
Question 15.
How will you control photochemical smog?
Answer:
The formation of photochemical smog can be suppressed by preventing the release of nitrogen oxide and hydrocarbons into the atmosphere from the motor vehicles by using catalytic convertors in engines. Plantation of certain trees like Pinus, Pyrus Querus vitus and Juniparus can metabolise nitrogen oxide.
Question 16.
What is meant by water pollution’?
Answer:
Water pollution is defined as the addition of foreign substances or factors like heat which degrades the quality of water so that it becomes an health hazard or unfit for use.
Question 17.
What are the sources of water pollution? Give examples.
Answer:
Question 18.
What is BOD’?
Answer:
The total amount of oxygen (in milligrams) consumed by microorganisms in decomposing the waste in one litre of water at 20°C for a period of 5 days is cal Led biochemical oxygen demand (BOD) and its value is expressed in ppm.
Question 19.
What is COD?
Answer:
Chemical oxygen demand (COD) is defined as the amount of oxygen required by the organic matter in a sample of water for its oxidation by a strong oxidising agent like K2Cr2O7 in acidic medium for a period of 2 hours.
Question 20.
What are total dissolved solids (TDS)?
Answer:
Question 21.
What are the constituents of soil?
Answer:
Soil is a thin layer of organic and inorganic material that covers the earth’s rocky surface. Soil constitutes the upper crust of the earth, which supports land, plants and animals.
Question 22.
Define – soil pollution.
Answer:
Soil pollution is defined as the build up of persistent toxic compounds, radioactive materials, chemical salts and disease causing agents in soil which have harmful effects on plant growth and animal health. Soil pollution affects the structure and fertility of soil, ground water quality and food chain in biological ecosystem.
Question 23.
Explain how industrial waste affects the soil.
Answer:
Question 24.
What is green chemistry?
Answer:
Question 25.
Write a note about dry cleaning of clothes.
Answer:
Solvents like tetrachioroethylene is used in dry cleaning of clothes, pollute the ground water and are carcinogenic. In place of tetrachloroethylene liquefied CO2 with suitable detergents an alternate solvent used. Liquefied CO2 is not that much harmful for the groundwater. Nowadays H2O2 is used for bleaching clothes in laundry that give better results and utilises less water.
Question 26.
Carbon monoxide gas is more dangerous than carbon dioxide gas. Why?
Answer:
Carbon monoxide gas combines with haemoglobin to form a very stable compound known as carboxy haemoglobin. When its concentration in blood reaches 3-4%, the oxygen carrying capacity of the blood is greatly reduced. This results into headache, nervousness and sometimes death of the person. On the other hand CO2 does not combine with haemoglobin and hence it is less harm ful than CO.
Question 27.
Which gases are responsible for greenhouse effect? List some of them.
Answer:
CO, is mainly responsible for greenhouse effect. Other greenhouse gases are methane, nitrous oxide, water vapours, CFCs and ozone.
Question 28.
A large number of fishes are suddenly found floating dead on a lake. There is no evidence of toxic dumping but you find an abundance of phytoplankton. Suggest a reason for the fish killing.
Answer:
Excessive phytoplankton (organic pollutants such as leaves, grass trash etc.) growth which is present in water is biodegradable. Bacteria decomposes this organic matter in water. During this process when large number of bacteria decomposes the organic matter, they consume the dissolved oxygen in water. When the level of dissolved oxygen falls below 6 ppm then the fishes cannot survive and they die.
Question 29.
How carbon monoxide acts as a poison for human beings’?
Answer:
Carbon monoxide is a poisonous gas because it combines with haemoglobin of RBC to form carboxyhaernoglobin as:
CO + Haemoglobin ⇌ Carboxyhaemoglobin
It inhibits the transport of oxygen to different pans of the body. Thus the body becomes oxygen-starved.
Question 30.
Give three examples in which the principles green chemistry has been applied.
Answer:
3 Marks Questions and Answers
Question 1.
Write about Bhopal gas tragedy.
Answer:
Question 2.
Explain how the oxides of sulphur pollute the atmospheric air. Give its haririful eflects.
Answer:
Question 3.
How oxides of nitrogen are harmful?
Answer:
(i) Oxides of nitrogen are produced during high temperature combustion processes, by oxidation of nitrogen in air and it is formed the combustion of fuels such as coal, diesel and petrol.
(iii) The oxides of nitrogen are converted into nitric acid which comes down in the form of acid rain. They also form reddish brown haze in heay traffic.
(iv) Nitrogen dioxide potentially damage plant leaves and retard photosynthesis.
(v) NO2 is a respiratory irritant and it can cause asthma and lung injury.
Question 4.
Explain how hydrocarbons pollute the atmospheric air.
Answer:
Question 5.
Write flotes about great London smog.
Answer:
Question 6.
What are the effects of classical smog?
Answer:
Question 7.
Explain how oxides of nitrogen are introduced directly into the stratosphere?
Answer:
Question 8.
How chemical wastes pollute water?
Answer:
Question 9.
Explain the presence of fluoride in water and its hazardous effects?
Answer:
Question 10.
Explain the harmful effects of
Answer:
Question 11.
Explain how styrene is produced by traditional and greener routes?
Answer:
1. Traditional route:
This method involve two steps-Carcinogenic benzene reacts with ethylene to form ethyl benzene. After that ethyl benzene undergoes dehydrogenation using Fe2O3 / Al2O3 to give styrene.
2. Greener route:
To avoid carcinogenic benzene. greener routes to start with cheaper and
environment friendly xylene.
Question 12.
How acetaldehyde is commercially prepared by green chemistry?
Answer:
Acetaldehyde is commercially prepared by one step oxidation of ethene in the presence of ionic catalyst in aoiieniis medium with 9% yield.
Question 13.
What do you mean by ozone hole? What are its consequences?
Answer:
Depletion of ozone layer creates some sort of holes in the blanket of ozone which surrounds us in the atmosphere and this is known as ozone hole.
Question 14.
What is photo chemical smog? What arc its effects? How can it be controlled?
Answer:
It is a kind of smog formed in warm, dry and sunny climate. It is formed when sunlight is absorbed by SO2 oxides of nitrogen and hydrocarbons. It act as an oxidising agent.
Effects of photo chemical smog:
Control of photochemical smog:
Question 15.
(a) Define eutrophication and pneumoconiosis.
(b) Write differences between photochemical smog and classical smog.
Answer:
(a) Eutrophication:
When the growth of algae increases in the surface of water, dissolved oxygen in water is greatly reduced. This phenomenon is known as eutrophication. Due to this growth of fishes gets inhibited.
(b) Pueumoconiosis:
It is a disease which irritates lungs. It causes scarring or fibrosis of the lungs.
Pholochemical smog:
Classical smog:
5 Marks Questions and Answers
Question 1.
Explain about the different layers of Earth’s atmosphere.
Answer:
Earth’s atmosphere can he divided into different layers with characteristic altitude and temperature.
Question 2.
What arc the health effects of particulate pollutants?
Answer:
1. Dust, mist, fumes etc. are air borne particles which are dangerous for human health. Particulate pollutants bigger than 5 microns are likely to settle in the nasal passage whereas particles of about 10 microns enter the lungs easily and causes scaring or fibrosis of lung lining.
They irritate the lungs and causes cancer and asthma. This disease is called pneumoconiosis. Coal miners may suffer from black lung disease. Textile workers may suffer from white lung disease.
2. Lead particulates affect children’s brain. interferes with maturation of RBC’s and even causes cancer.
3. Particulates in the atmosphere reduces the visibility by scattering and absorption of sun light. It is dangerous for aircraft and motor vehicles.
4. Particulates provide nuclei for cloud formation and increases fog and rain.
5. Particulates deposit on plant leaves and hinder the intake of CO2 from the air and affect photosynthesis.
Question 3.
What arc the effects of photochernical smog?
Answer:
Question 4.
Explain about the environmental impacts of ozone depletion.
Answer:
1. The formation and destruction of ozone is a regular natural process, which never disturbs the equilibrium level of ozone in the stratosphere. Any change in the equilibrium level of ozone in the atmosphere will adversely affect the Life in biosphere in the following ways.
2. Depletion of ozone layer will allow more UV rays to reach the earth surface and would cause skin cancer and also decreases the immunity level in human beings.
3. UV radiations atlecis plant proteins which lead to harniful mutation in plant cells.
4. UV radiations affect the growth of phytoplankton and as a result ocean food chain is disturbed and it even damages the fish productivity.
Question 5.
Explain the list of major water pollutants and their sources.
Answer:
Question 6.
Describe about the causes of water pollution.
Answer:
Causes of water pollution –
1. Microbiological pollutants:
(a) Disease causing microorganisms like bacteria, viruses and protozoa are most senous water pollutants. They come from domestic sewage and animal excreta.
(b) Fish and shellfish can become contaminated from them and people who eat them will also become ill.
(c) Dysentery and cholera are water borne diseases.
(d) Human excrcta contain bacteria such as Escherichia coll and Streptococcus farcical- -is which causes gastrointestinal diseases.
2. Organic wastes:
Organic matter such as leaves, grass, trash can also pollute water. Water pollution is cause by excessive phytoplankton growth within water.
3. Chemical wastes:
A whole variety of chemicals from industries such as metals and solvents are poisonous to fish and other aquatic life. Detergents and oils float spoils the water bodies. Acids from mine drainage and salts form various sources can also contaminate water sources.
Question 7.
What are the harmful effects of chemical water pollutants’?
Answer:
Question 8.
Explain about green chemistry in day-to-day life.
Answer:
1. Dry cleaning of clothes:
Solvents like tetrachloroethylene used in dry cleaning of clothes, pollute the ground water and are carcinogenic. In place of tetrachloro ethylene, liquefied CO2 with suitable detergent is an alternate solvent used. Liquefied CO2 is not harmful to the ground water. Nowadays H2O2 is used for bleaching clothes in laundry, gives better result and utilises less water.
2. Bleaching of paper:
Conventional method of bleaching was done with chlorine. Nowadays H2O2 can be used for bleaching paper in the presence of catalyst.
3. Synthesis of chemicals:
Acetaldehyde is commercially prepared by one step oxidation of ethane in the presence of ionic catalyst in aqueous medium with 90% yield.
4. Instead of petrol, methanol is used as a fuel in automobiles.
5. Neem based pesticides have been synthesized, which are more safer than the chlorinated hydrocarbons.