Important Questions for Class 11 Chapter 14 - Environmental Chemistry

Important questions based on NCERT syllabus for Chapter 14 - Environmental Chemistry:

Question-1: Explain the tropospheric pollution in 100 words?

Solution: Tropospheric pollution occurs due to the presence of undesirable substance in air. These may be the solid or gaseous pollutants.

Gaseous Air Pollutants: These are oxides of sulphur, nitrogen and carbon, hydrogen sulphide, hydrocarbons, ozone and other oxidants.
Particulate Pollutants: These are dust, mist, fumes, and smog etc.

Question-2: Carbon monoxide gas is more dangerous than carbon dioxide gas. Why?

Solution: Carbon monoxide combines with haemoglobin to form a very stable compound known as carboxyhaemoglobin when its concentration in blood reaches 3-4%, the oxygen carrying capacity of the blood is greatly reduced. This results into headache, nervousness and sometimes death of the person. On the other hand CO2 does not combine with haemoglobin and hence is less harmful than CO.

Question-3: What is smog? How is classical smog different from photochemical smog?

Solution: The word smog is a combination of smoke and fog. It is a type of air pollution that occurs in many cities throughout the world. Classical smog occurs in cool humid climate. It is also called as reducing smog.Whereas photochemical smog occurs in warm and dry sunny climate. It has high concentration of oxidising agents and therefore, it is also called as oxidising smog.

Question-4: What do you mean by ozone hole? What are its consequences?

Solution: Depletion of ozone layer creates some sort of holes in the blanket of ozone which surround us, this is known as ozone hole.

With the depletion of the ozone layer, UV radiation filters into the troposphere which leads to aging of skin, cataract, sunburn, skin cancer etc.
By killing many of the phytoplanktons, it can damage the fish productivity.
Evaporation rate increases through the surface and stomata of leaves which can decrease the moisture content of the soil.