Chemistry

Environmental Chemistry

Question:

The pollutants which come directly in the air from source are called primary pollutants. Primary’pollutants are sometimes converted into secondary pollutants. Which of the following belongs to secondary air pollutants?
(a) CO
(b) Hydrocarbon
(c) Peroxyacetyl nitrate                                              
(d) NO

Answer:

Hydrocarbons present in atmosphere combine with oxygen atom produced by the photolysis of N02 to form highly reactive intermediate called free  radical. Free radical initiates a series of reactions.Peroxyacetyl nitrate is formed, which Gan be said as secondary pollutant.
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Environmental Chemistry

Q 1.

Ozone is a toxic gas and is a strong oxidizing agent, even then its presence in the stratosphere is very important. Explain what would happen if ozone from this region is completely removed.

Q 2.

What are the sources of dissolved oxygen in water?

Q 3.

A person was using water supplied by Municipality. Due to shortage of water, he started using underground water. He felt laxative effect. What could be the cause?

Q 4.

What would have happened if the greenhouse gases were totally missing in the earth’s atmosphere? Discuss.

Q 5.

Assertion (A): Carbon dioxide is one of the important greenhouse gases. Reason (R): It is largely produced by respiratory function of animals and plants.
(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) Both A and R are not correct.
(d) A is not correct but R is correct.

Q 6.

Oxidation of sulphur trioxide in the absence of a catalyst is a slow process but this oxidation occurs easily in the atmosphere. Explain how does this happen. Give chemical reactions for the conversion of S02 into S03.

Q 7.

What do you mean by Biochemical Oxygen Demand (BOD)?

Q 8.

How can domestic waste be used as manure?

Q 9.

What is chlorosis?

Q 10.

Assertion (A): The pH of acid rain is less than 5.6.
Reason (R): Carbon dioxide present in the atmosphere dissolves in rain water and forms carbonic acid.
(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) Both A and R are not correct.
(d) A is not correct but R is correct.

Q 11.

Assertion (A): If BOD level of water in a reservoir is less than 5 ppm it is highly polluted.
Reason (R): High biological oxygen demand means low activity of bacteria in 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) Both A and R are not correct.
(d) A is not correct but R is correct.

Q 12.

Carbon monoxide gas is more dangerous than carbon dioxide gas. Why?

Q 13.

What is the importance of measuring BOD of a water body?

Q 14.

What is meant by polar vortex?

Q 15.

What are the harmful effects of photochemical smog and how can they be controlled? 

Q 16.

How are NO and NO2 formed in the atmosphere?

Q 17.

How carbon monoxide acts as a poison for human beings?

Q 18.

What is photochemical smog? What are its effects? How can it be controlled?

Q 19.

On the basis of chemical reactions involved, explain how do chlorofluoro- carbons cause thinning of ozone layer in stratosphere.

Q 20.

Assertion (A): Photochemical smog is oxidizing in nature.
Reason (R): Photochemical smog contains N02 and 03, which are formed during the sequence of reactions.
(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) Both A and R are not correct.
(d) A is not correct but R is correct.

Q 21.

What is the nature of classical smog?

Q 22.

What are pesticides and herbicides? Explain giving examples.

Q 23.

What is BOD?

Q 24.

What are pesticides ?

Q 25.

Give the examples of insecticides.

Q 26.

Why does water covered with excessive algal growth become polluted?

Q 27.

What do you mean by ozone hole? What are its consequences?

Q 28.

What do you mean by green chemistry? How will it help in decreasing environmental pollution ?

Q 29.

List out the gases which are considered as major source of air pollution.

Q 30.

What is ‘Acid Rain’? How is it harmful to the environment?

Q 31.

Acid rain is known to contain some acids. Name these acids. From where do they come in rain?

Q 32.

What could be the harmful effects of improper management of industrial and domestic solid waste in a city?

Q 33.

Assertion (A): Excessive use of chlorinated synthetic pesticides causes soil and water pollution.
Reason (R): Such pesticides are non-biodegradable.
(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) Both A and R are not correct.
(d) A is not correct but R is correct.

Q 34.

Why is acid rain considered as threat to Taj Mahal ?

Q 35.

During an educational trip, a student of Botany saw a beautiful lake in a , village. She collected many plants from that area. She noticed that villagers were washing clothes around the lake and at some places, waste material from houses was destroying its beauty. After few years, she visited the same r lake again. She was surprised to find that the lake was covered with algae, stinking smell was coming out and its water had become unusable. Can you explain the reason for this condition of the lake?

Q 36.

Match the terms given in Column I with the compounds given in Column

Column 1 Column  II
(a) Acid rain (1) CHC12-CHF2
(b) Photochemical smog (2) CO
(c) Combination with haemoglobin (3) co2
(d) Depletion of ozone layer (4) so2
    (5) Unsaturated hydrocarbons

 

Q 37.

Define environmental chemistry?

Q 38.

Which gases are responsible for greenhouse effect? List some of them.

Q 39.

What are the reactions involved for ozone layer depletion in the stratosphere?

Q 40.

Which main gases is responsible for damage in ozone layer?

Q 41.

(a) Define eutrophication and pneumoconiosis.
(b) Write difference between photochemical and classical smog.

Q 42.

What is meant by PCBs?

Q 43.

Give one example of organic herbicide.

Q 44.

What is PAN stands for?

Q 45.

Biochemical Oxygen Demand, /BOD) is a measure of organic material present in water. BOD value less than 5 ppm indicates a water sample to be

Q 46.

Which of the following statements is correct?
(a) Ozone hole is a hole formed in stratosphere from which ozone oozes out.
(b) Ozone hole is a hole formed in the troposphere from which ozone oozes out.                                                                                                                                                 .
(c) Ozone hole is thinning of ozone layer of stratosphere at some places.
(d) Ozone hole means vanishing of ozone layer around the earth completely.

Q 47.

What are biodegradable and non-biodegradable pollutants? ,

Q 48.

A factory was started near a village. Suddenly villagers started feeling the presence of irritating vapours in the village and cases of headache, chest pain, cough, dryness of throat and breathing problems increased. Villagers blamed the emissions from the chimney of the factory for such problems. Explain what could have happened. Give chemical reactions for the support of your explanation.

Q 49.

Ozone is a gas heavier than air. Why does ozone layer not settle down near the earth?

Q 50.

What are the major causes of water pollution? Explain.