Question

Below which of the following pH is rain regarded as ‘acid rain’?

(a) 7

(b) 7.3

(c) 5.6

(d) 6

This question was posed to me in class test.

I'd like to ask this question from Acid Rain in division Particulates, Acid Rain & Aerosols of Environmental Engineering

Answer 1

The correct option is (c) 5.6

To explain I would say: Though the pH of neutral water is 7, rain water is acidic due to mixing up with atmospheric carbon dioxide and is said to have a 5.6 pH. Hence acid rain has a pH less than 5.6.