Chemistry

Environmental Chemistry

Question:

What are the major causes of water pollution? Explain.

Answer:

Causes of water pollution:

  • Pathogens: Pathogens include bacteria and other microorganisms that enter water from domestic sewage and animal excreta.
    Human excreta contain bacteria such as Escherichia coli and Streptococcus faecalis ,
    which cause gastrointestinal diseases.
  • Organic wastes: Organic wastes when added to water, as these are biodegradable, bacteria decomposes organic matter and consume dissolved oxygen in water. When the concentration of dissolved oxygen of water is below 6 ppm, the growth of fish gets inhibited. Breakdown of the organic wastes by anaerobic bacteria produces chemicals that have a foul smell and are harmful to human health.
  • Chemical pollutants: Some inorganic chemicals as an industrial wastes dissolve in water like cadmium, mercury nickel etc. These metals are dangerous to humans and other animals. These metals can damage kidneys and central nervous system,lever etc. Petroleum products pollute many sources of water.
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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.

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

Q 3.

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 4.

How can domestic waste be used as manure?

Q 5.

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

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.

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

Q 8.

Why is acid rain considered as threat to Taj Mahal ?

Q 9.

What are the sources of dissolved oxygen in water?

Q 10.

Which of the following conditions shows the polluted environment?
(a) pH of rain water is 5.6.
(b) Amount of carbon dioxide in the atmosphere is 0.03%.
(c) Biochemical oxygen demand is 10 ppm.
(d) Eutrophication

Q 11.

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

Q 12.

What is PAN stands for?

Q 13.

What do you mean by viable and non-viable particulates?

Q 14.

What is siltation?

Q 15.

Which zone is known as ozonosphere?

Q 16.

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 17.

What is smog? How is classical smog different from photochemical smog?

Q 18.

What is BOD?

Q 19.

Why does water covered with excessive algal growth become polluted?

Q 20.

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 21.

How carbon monoxide acts as a poison for human beings?

Q 22.

From where does ozone come in the photochemical smog?

Q 23.

What are pesticides and herbicides? Explain giving examples.

Q 24.

What is the name of the compound formed when CO combines with blood?

Q 25.

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 26.

Define environmental chemistry?

Q 27.

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

Q 28.

What is meant by PCBs?

Q 29.

What are the major causes of water pollution? Explain.

Q 30.

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

Q 31.

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

Q 32.

Which main gases is responsible for damage in ozone layer?

Q 33.

What is the nature of classical smog?

Q 34.

Which gas was mainly responsible for Bhopal gas tragedy?  

Q 35.

What are biodegradable and non-biodegradable pollutants? ,

Q 36.

For your agricultural field or garden you have developed a compost producing pit. Discuss the process in the light of bad odour, flies and recycling of wastes for a good produce.

Q 37.

How are NO and NO2 formed in the atmosphere?

Q 38.

What is chlorosis?

Q 39.

What is the compound formed when CO combines with blood?

Q 40.

The acids present in acid rain are________ .
(a) Peroxyacetylnitrate                                                
(b) H2C03
(c) HN03                                                                                                    
(d) H2S04

Q 41.

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

Q 42.

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 43.

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 44.

Assertion (A): Ozone is destroyed by solar radiation in upper stratosphere.
Reason (R): Thinning of the ozone layer allows excessive UV radiations to reach the surface of 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) Both A and R are not correct.
(d) A is not correct but R is correct.

Q 45.

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

Q 46.

What is the composition of London Smog?

Q 47.

What are pesticides ?

Q 48.

What do you mean by greenhouse effect? What is the role of CO2 in the greenhouse effect?

Q 49.

Phosphate containing fertilizers cause water pollution. Addition of such compounds in water bodies causes
(a) enhanced growth of algae
(b) decrease in amount of dissolved oxygen in water
(c) deposition of calcium phosphate
(d) increase in fish population

Q 50.

Greenhouse effect leads to global warming. Which substances are responsible for greenhouse effect?