A large number of fish are suddenly found floating dead on a lake. There is no evidence of toxic dumping but you find an abundance of phytoplankton. Suggest reason for the fish kill.

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

What do you mean by green chemistry? How will it help decrease environmental pollution?
Or
Comment: 'Green chemistry is an alternative tool for reducing pollution'

Have you ever observed any water pollution in your area? What measures would you suggest to control it?

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

Do you observe any soil pollution in your neighbourhood? What efforts will you make for controlling the soil pollution?

97.

Ozone is present as a chief constituent in which region of the atmosphere?

• Troposphere

• Stratosphere

• Mesosphere

• Thermosphere

The gas leaked from a storage tank of the Union Carbide plant in Bhopal tragedy was

• Methyl isocyanate

• Methylamine

• Ammonia

• Ammonia

A water sample has ppm level concentration of following anions

F^-= 10; SO₄^2- =100; NO₃^-= 50

the anion/anions that make/makes the water sample unsuitable for drinking is /are:

• only NO₃^-

• both 2 SO₄^- and NO₃^-

• only F^– 

• only F^– 

Identify the wrong statements in the following:

• Chlorofluorocarbons are responsible for ozone layer depletion

• Greenhouse effect is responsible for global warming

• Ozone layer does not permit infrared radiation from the sun to reach the earth

• Ozone layer does not permit infrared radiation from the sun to reach the earth