Sulphur dioxide is one of the components of polluted air. SO _ 2 is...

Acid rain is a by product of a variety of human activities that emit the oxides of sulphur and nitrogen in the atmosphere. As mentioned earlier, burning of fossil fuels (which contain sulphur and nitrogenous matter) such as coal and oil in power stations and furnaces or petrol and diesel in motor engines produce sulphur dioxide and nitrogen oxides. ${SO}_{2}$ and ${NO}_{2}$ after oxidation and reaction with water are major contributors to acid rain, because polluted air usually contains particulate matter that catalyse the oxidation.

$2{SO}_{2}\left(g\right) + {O}_{2}\left(g\right) + 2{H}_{2}O\left(l\right) \to 2{H}_{2}{SO}_{4}\left(aq\right)$

$4{NO}_{2}\left(g\right) + {O}_{2}\left(g\right) + 2{H}_{2}O\left(l\right) \to 4{HNO}_{3}\left(aq\right)$