What is acid rain?

"Acid rain" is a mixture of wet and dry deposition i.e. deposited material from the atmosphere containing higher than normal amounts of nitric and sulfuric acids.

Acid Rain:

Acid rains are usually acidic which possesses elevated levels of hydrogen ions (low pH). Acid rain is mainly caused by emissions of harmful gaseous such as ##SO_2## (sulphur dioxide) and different oxides of nitrogen which react with the water molecules in the atmosphere to produce acids.

Acid rains mainly refer to the deposition of wet (rain, snow, sleet, fog, cloudwater, and dew) and dry (acidifying particles and gases) acidic components.

As we know that liquids with a less than 7 are acidic, and those with a pH greater than 7 are alkaline. "Clean" or unpolluted rain has an acidic pH, but usually no lower than 5.7, because carbon dioxide and water in the air react together to form carbonic acid, a weak acid.