Chemistry

Environmental Chemistry

Question:

Give three examples in which green chemistry has been applied.

Answer:

  • In dry-cleaning, use of liquefied CO2 in place of tetrachloroethene (Cl2C = CCl2).
  • In bleaching of paper using H2O2 in place of chlorine.
  • In the manufacture of chemicals like ethanal using environment-friendly chemicals and conditions.
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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.

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 4.

How can domestic waste be used as manure?

Q 5.

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

Q 6.

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 7.

What is BOD?

Q 8.

What is siltation?

Q 9.

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

Q 10.

Match the activity given in Column I with the type of pollution created by it given in Column II.

Column I Column II  
Releasing gases to the atmosphere after burning waste material containing Sulphur. 0) Water pollution
Using                     carbamates  as pesticides. (2) Photochemical smog, damage to plant life, corrosion to building material, induce breathing problems, water pollution
Using synthetic detergents for washing clothes. (3) Damaging ozone layer
Releasing gases produced by automobiles and factories in the atmosphere. (4) May cause nerve diseases in human                                                                         .
Using chlorofluorocarbon compounds for cleaning computer parts. (5) Classical smog, acid rain, water pollution, induce breathing problems, damage to buildings, corrosion of metals

 

Q 11.

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

Q 12.

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

Q 13.

What are biodegradable and non-biodegradable pollutants? ,

Q 14.

From where does ozone come in the photochemical smog?

Q 15.

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

Q 16.

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

Q 17.

What is the compound formed when CO combines with blood?

Q 18.

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

Q 19.

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 20.

Define environmental chemistry?

Q 21.

What are pesticides and herbicides? Explain giving examples.

Q 22.

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

Q 23.

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 24.

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

Q 25.

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

Q 26.

Why is acid rain considered as threat to Taj Mahal ?

Q 27.

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

Q 28.

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

Q 29.

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 30.

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 31.

Assertion (A): Greenhouse effect was observed in houses used to grow plants and these are made of green glass.
Reason (R): Greenhouse name has been given because glass houses are made of green glass.
(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 32.

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 33.

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

Q 34.

What do you mean by primary and secondary pollutants of the air?

Q 35.

Which zone is known as ozonosphere?

Q 36.

Which main gases is responsible for damage in ozone layer?

Q 37.

What is PAN stands for?

Q 38.

Which gas was mainly responsible for Bhopal gas tragedy?  

Q 39.

What is meant by polar vortex?

Q 40.

What should be the tolerable limit of F ions in drinking water?

Q 41.

How carbon monoxide acts as a poison for human beings?

Q 42.

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

Q 43.

What is meant by PCBs?

Q 44.

Give three examples in which green chemistry has been applied.

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.

Dinitrogen and dioxygen are main constituents of air but these do not react with each other to form oxides of nitrogen because____________ .
(a) the reaction is endothermic and requires very high temperature.
(b) the reaction can be initiated only in presence of a catalyst.
(c) oxides of nitrogen are unstable.
(d) N2 and 02 are unreactive,

Q 47.

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

Q 48.

Dissolved oxygen in water is v £ry important for aquatic life. What processes are responsible for the reduction of dissolved oxygen in water?

Q 49.

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 50.

Why does water covered with excessive algal growth become polluted?