Consider the following:
- Carbon monoxide
- Nitrogen oxide
- Ozone
- Sulfur dioxide
Excess of which of the above in the environment is/ are the cause(s) of acid rain?
- 1, 2 and 3
- 2 and 4 only
- 4 only
- 1, 3 and 4
Explanation
Option (b) is correct
- Acid rain, or acid deposition, is a broad term that includes any form of precipitation with acidic components, such as sulfuric or nitric acid, that fall to the ground from the atmosphere in wet or dry forms. This can include rain, snow, fog, hail, or even acidic dust. When the pH of the rainwater drops below. 5.6, it is called acid rain. It is caused by atmospheric pollution from acidic gases such as sulphur dioxide and oxides of nitrogen emitted from the burning of fossil fuels. It is also recognised that acidic smog, fog, and mist move out of the atmosphere and settle on dust particles, which in turn accumulate on vegetation as acid depositions. When rain falls, the acid from these depositions leak and form acid dews.
- Ozone is not a direct contributor to acid rain; although it has harmful environmental effects, it does not act as a precursor in its formation. Similarly, carbon monoxide, while a pollutant that helps in the formation of ground-level ozone, does not play a role in causing acid rain
- Gases that cause acid rain:
| Acidic gases | Source |
| SOx (Sulphur oxides) | Fossil fuel burning, power plants, smelting of metal sulphide ores, industrial sources, industrial production of sulfuric acid in metallurgical, chemical and fertiliser industries, volcanoes, seas and oceans, decomposition of organic matter. |
| NOx (Nitrogen oxides – NO, NO2 and N2O) | Fossil fuel burning, lightning, biomass burning, forest fires, oceans, power plants.
(NO and N2O are mentioned in the NIOS Environment) |
