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.


(i) Both A and R are correct and R is the correct explanation of A.


(ii) Both A and R are correct but R is not the correct explanationof A.


(iii) Both A and R are not correct.


(iv) A is not correct but R is correct.


(ii) Both A and R are correct but R is not the correct explanationof A.

Explanation:Acid rain is the rain which has been acidified by the chemicals present in the atmosphere. Due to the presence of pollutants or chemicals released from the industry (industrial smoke) or vehicular exhaust like sulphur oxides and nitrogen oxides, they react with the water vapours or water droplets andform acids of respective non-metals which in turn results in thelowering of the pH of the rain. Sometimes, carbon dioxide present in the atmosphere can also lead to lowering of pH of rain, but it isnot the sole factor responsible for lowering the pH of rain to less than 5.6.


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