Question

What is Acid Rain? 

Answer 1

1. Acid rain means rainfall with a pH of less than 5.6. About 80% of oxides of sulphur come from burning of fossil fuels. Sulphur trioxide on reaction with water produces sulphuric acid \[\ce{(H2SO4)}\]. This is the principal (60-70 per cent) cause of acid rain.
2. Acid rain is essentially an outcome of aggressive industrialisation in the developed countries. It is caused by both nature and human activities.