What is acid rain? State its impact on the environment.

Acid rain means the presence of excessive acids in rainwater.

Burning of coal, wood and petroleum produce sulphur and nitrogen. These two react with oxygen and are converted into their respective oxides- sulphur dioxide and nitrogen dioxide, which are soluble in water.

During rain, these oxides react with large quantities of water vapour in the atmosphere to form acids like sulphuric acid, sulphurous acid, nitric acid and nitrous acid. These acids, when they precipitate together with rain or snow form acid rain.

Impact of acid rain on the environment are as follows-

1. Acid rain increases the acidity in the soil and destroys forests and crops.
2. It corrodes buildings, monuments, statues, bridges, fences and railings.
3. It poses a serious threat to human health, since it contaminates air and water.
4. Aquatic species are affected due to acid rain.
5. Acid rain affects plant growth. Plant leaves get burnt and dry.