What is acid rain?

Answer 1

Acid precipitation is rain (or other precipitation) that is unusually acidic ( has a pH below 6). The main pollutants that cause this problem are sulfur oxides (SOx) and nitrogen oxides (NOx) . These combine with water in the atmosphere to produce Sulfurous and Sulphuric Acid, and Nitrous and Nitric Acid.

When fuels such as coal, oil and petrol are burned or when sulfidic ores are processed they release sulphur dioxide and other gases into the air. These gases dissolve in droplets of moisture in the atmosphere and eventually produce an acid rain.

Acid rain can have a direct effect on plants (phytotoxicology) or on the soil structure of the ground the plants grow in. It can also release metals from limestones soil, change the pH of water in streams and lakes, and corrode metal and stone artifices.

Rain with an acid content. The acid, especially sulphuric acid, is the result of pollution, from industry, cars, etc.

A:

Acid rain is rain with a Ph of less than 6.

This Ph is usually caused by dissolving atmospheric gasses such as CO2 or SO2 in the moisture in the Air making Carbonic or Sulfuric acid.

Human activities like burning fossil fuels and agricultural fertilization as well as natural events like volcanic eruptions release carmon and sulfur dioxide into the atmosphere. These pollutants undergo chemical changes in the atmosphere and eventually dissolve in atmospheric moisture to form acids. When the moisture falls back to earth as rain or snow, the effect is acid rain.

Note that normal rain can be slightly acidic due to natural dissolved carbon dioxide. This is not generally what is meant by "acid rain." Even so, the weak carbonic acid formed this way can have dramatic effects, like dissolving limestone to form vast underground caves. When Nitric and Sulfuric acid level is high, they react with droplets of water in clouds and form nitric and sulfuric acid, which is known as acid rain.