Which of the following is not a cause of acid precipitation?
Scientists measure the acidity of an object using the pH scale. The scale ranges from 0 to 14, with a pH of 7 being considered neutral. A pH less than 7 is acidic and one more than 7 is basic or alkaline. Normal rain has a pH of about 5.6. It is not neutral because rainwater naturally dissolves a small amount of carbon dioxide from the air and becomes slightly acidic.
Acid rain becomes a serious problem when the pH of the precipitation becomes less than 3.5. There have been reported pH of 1.3 in some areas. These extremely acidic conditions kill fish and plants, and may render lakes and soil totally uninhabitable. Young fish not only are killed by such acidic waters, but any fish that may survive are usually not able to reproduce. Sometimes, nature provides a means of neutralizing these acidic waters via naturally alkaline ammonia compounds or calcium compounds such as limestone,
The list below gives the pH of some common substances:
1.1: Battery acid
2.8: Household vinegar
5.5: Normal rainwater
7.0: Distilled water
8.2: Baking soda
11.6: Household ammonia
Hydroelectric plants do not burn fossil fuels to generate electricity. All of the other choices are specifically mentioned as contributing to acid rain.