Acid Rain

Acid rain is the rainfall characterised by such a higher level of presence of acids in the rain-water that becomes harmful for the environment.

It is also called "acid precipitation" or "acid deposition". Acid precipitation contains harmful amounts of nitric and sulfuric acids formed primarily by nitrogen oxides and sulfur oxides released into the atmosphere when coal or other fossil fuels are burned. Industrial burning of coal or other fossil fuels also emits waste gases containing sulfur and nitrogen oxides. These waste gases then combine with the rain-water to form acids.

There can also be wet precipitation (rain, snow, or fog) or dry precipitation (absorbed gaseous and particulate matter, aerosol particles, or dust).

Acid rain has a pH below 5.6.
Normal rain has a pH of about 5.6, which is slightly acidic.

It may be mentioned here that the pH value is a measure of acidity or alkalinity, ranging from 0 to 14. A pH measurement of 7 is regarded as neutral. Measurements below 7 indicate increased acidity, and those above 7 indicate increased alkalinity.

Nearby pages
Acid reflux, Acid rock, Acid salt, Acid test, Acid Test Ratio, Acidimetry