A factory was started near a village. Suddenly villagers started feeling the presence of irritating vapors 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. This is : 

1. Due to the burning of fossil fuels such as gasoline, coal, natural gas, etc.

2. Due to the burning of toxic soil.

3. Due to the burning of white Phosphorus in soil.

4. Due to Excessive sound pollution.

Acid rain occurs due to the oxidation of : 

1. Carbon, sulphur (unsaturated hydrocarbon) and nitrogen.

2. Ethanol.

3. Methanol.

4. Methane.

Green plants use carbon dioxide for photosynthesis and return oxygen to the atmosphere. Even then carbon dioxide is considered to be responsible for green house effect : 

1. Due to an increase in atmospheric temperature.

2. Due to ozone depletion.

3. Due to decrease in atmospheric temperature.

4. Due to an increase in chlorophyll concentration.

A farmer was told that fishes were not fit for human consumption because a large amount of pesticides had accumulated in the tissues of fishes. This happens:

1. By the transfer of pesticides in the food chain.

2. By the degradation of pesticides.

3. By the reaction of pesticides with atmospheric oxygen.

4. By the reaction of pesticides with atmospheric carbon dioxide.

The best alternative of tetrachloroethane for dry cleaning is-

1. Liquified CO₂ along with suitable detergent.

2. Liquified CO₂ along with suitable oil.

3. Liquified SO₂ along with suitable detergents.

4. Liquified SO₂ along with suitable oil.

Mercury, aluminum, lead, copper, DDT, etc. are an example of :

1. Biodegradable Pollutant.

2. Non-biodegradable pollutant.

3. Non pollutant.

4. Noise pollutant.

When a lake get covered with algae, a stinking smell comes out and its water becomes unpotable. The reason for such a condition of the lake is-

1. Eutrophication.

2. Excess of oxalate ions in water.

3. Excess of non-biodegradable waste in water.

4. Excess of photosynthesis.

Ozone is a very toxic gas and a strong oxidizing agent. It is still useful for life on earth :

1. because it traps harmful UV-rays.

2. because it balances global warming.

3. because it traps harmful X-rays.

4. because it  traps harmful $\mathrm{\gamma }$-rays.

Which, of the following, gases contributes  nearly 50 % to the green house effect (which, in turn, causes global warming) ?

1. SO₂

2. SO₃

3. CO₂

4. Water vapour

The chemical that is an excellent ‘green’ solvent as well as a greenhouse gas is: 

1. Methanol

2. CFCs

3. Carbon monoxide

4. Carbon Dioxide