• # question_answer Acid rains are produced by : A)  excess $N{{O}_{2}}$ and $S{{O}_{2}}$ from burning fossil fuels B)  excess production of $N{{H}_{3}}$ by industry and coal gas C)  excess release of carbon monoxide by incomplete combustion D)  excess formation of $C{{O}_{2}}$ by combustion and animal respiration.

When fossil fuel burnt in automobile engines different oxides like $NO,\,N{{O}_{2}},\,S{{O}_{2}},\,S{{O}_{3}}$ are produced. In the presence of moisture these oxides convert in the acids. These acids comes down from the atmosphere in the form of rain, called acid rain. $S{{O}_{2}}+{{O}_{3}}\xrightarrow{\,}\,S{{O}_{3}}+{{O}_{2}}$ $S{{O}_{2}}+{{H}_{2}}{{O}_{2}}\xrightarrow{\,}\,{{H}_{2}}S{{O}_{4}}$ $S{{O}_{3}}+{{H}_{2}}O\xrightarrow{{}}\,{{H}_{2}}S{{O}_{4}}$ $2N{{O}_{2}}+{{H}_{2}}O\xrightarrow{\,}\,HN{{O}_{3}}+HN{{O}_{2}}$