acid rain answer: carbon dioxide from air dissolve in rainwater to make a weak acid. this is a natural process and does not harm the environment. however burning of coal, oil in power satations and the increase in motor vehicles are have more serious effect on environment. sulphur dioxide is produced when coal and oil burn and is released into the atmosphere. sulphur dioxide dissolves in rainwater to form sulphuric acid. this is strong acid and therefore makes the rain more acidic. Effect of acid rain: Acid rain harm palnts and water life and eats into stonework, especially if it is made of limestone. for instance, taj mahal