EVERYDAY SCIENCE

Detailed explanation-1: -Normal, clean rain has a pH value of between 5.0 and 5.5, which is slightly acidic. However, when rain combines with sulfur dioxide or nitrogen oxides-produced from power plants and automobiles-the rain becomes much more acidic. Typical acid rain has a pH value of 4.0.

Detailed explanation-2: -(pH 5.0 to 5.8) Moderately acid. (pH of 5.5 to 6.8) Slightly acid.

Detailed explanation-3: -Uncontaminated precipitation is naturally acidic. Water contains atmospheric gases as well as carbon dioxide, and when the carbon dioxide dissolves it forms carbonic acid, which makes the pH of normal rain about a 5.6 on the pH scale.

Detailed explanation-4: -Rain water with a pH less than 5.6 is called Acid rain.