Gases responsible for acid rain are

when rain combines with sulphur dioxide or nitrogen oxides then it is called as acid rain which is usually produced from power plants and automobiles.

The formation of acid is given as follows:

$$\begin{gathered} 2{\mathrm{SO}}_2( \mathrm{g})+{\mathrm{O}}_2( \mathrm{g})+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{I}\right)\to 2{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right) \\ 4{\mathrm{NO}}_2( \mathrm{g})+{\mathrm{O}}_2( \mathrm{g})+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{I}\right)\to 4{\mathrm{HNO}}_3\left(\mathrm{aq}\right) \end{gathered}$$