Chemistry · Ch 15 — Environmental Chemistry
Acid Rain
Acid Rain
Rain water normally has a pH of about 5.6, because of the dissolution of atmospheric CO₂ into it. Oxides of sulphur and nitrogen present in the atmosphere may be absorbed by the water droplets that make up clouds, and get chemically converted there into sulphuric acid and nitric acid respectively. When this pushes the pH of rain-water drops below 5.6, it is called acid rain.
Acid rain is a by-product of a variety of sulphur and nitrogen oxides in the atmosphere. Burning fossil fuels (coal and oil) in power stations and furnaces, and petrol/diesel in motor engines, produces sulphur dioxide and nitrogen oxides -- the main contributors to acid rain are SO₂ and NO₂, which convert into sulphuric acid and nitric acid respectively by reaction with oxygen and water:
Harmful effects of acid rain:
- (i) It causes extensive damage to buildings and structural materials made of marble -- this attack on marble is termed Stone leprosy:
- (ii) It affects plant and animal life in the aquatic ecosystem.
- (iii) It is harmful for agriculture, trees and plants, since it dissolves and removes the nutrients needed for their growth. …
Worked out. Five harmful effects listed in the book: (i) acid rain causes extensive damage to buildings and marble structural materials -- this attack on marble, , is termed Stone leprosy; (ii) it affects plant and animal life in the aquatic ecosystem; (iii) it is harmful to agriculture, trees and plants, dissolving and removing nutrients needed for growth; (iv) it corrodes water pipes, leaching heavy metals such as iron, lead and copper into drinking water with toxic effect; (v) it causes re …
What this figure shows. A photograph of the Taj Mahal's white marble domes and minarets under a blue sky, used to illustrate how acid-rain-driven reaction with marble (Stone leprosy) damages and discolours this monument's surface over time …