Question

Acid rain is formed, when the pH of rain water is ________.

• A. less than 6
• B. more than 7
• C. Equal to 7
• D. Equal to 10

Answer 1

The correct option is A

less than 6

The rain containing excess of acids is called an acid rain. The rain becomes acidic because carbon dioxide, sulphur dioxide and nitrogen dioxide (which are released into the air as pollutants) dissolve in rain drops to form carbonic acid, sulphuric acid and nitric acid respectively. When pH of rain water is less than 5.6, it is called acid rain.