Solution:
Damage to Taj Mahal (made up of marble) is caused by acid rain. Acid rain is rainfall and other forms of precipitation with a pH of less than 5. It consists of acids such as sulphuric acid and nitric acid. It corrodes metals, marbles, slate, stone etc. This phenomenon is called stone leprosy. Etching of marble occurs due to conversions of calcium carbonate of marble into calcium sulphate and calcium nitrate by \(\mathrm{H}_{2} \mathrm{SO}_{4}\) and \(\mathrm{HNO}_{3}\) respectively.
