Question

If acids are compounds that release protons (H+), how is it that `SO_x` and `NO_x` cause acid rain?

Answer 1

The compounds react with water to form new compounds that can release protons.

Explanation:

`SO_2 + H_2O === H_2SO_3`

`H_2SO_3` sulfurous acid can easily release protons because of the resonance structure of `SO_3`

`SO_3 + H_2O === H_2SO_4`

`H_2SO_4` sulfuric acid is even stronger than sulfurous acid. The `SO_4` sulfate ion has a resonance structure that allows easy release of the hydrogen ions.

These nonmetal gases are very soluble in water. The sulfur oxides dissolve in the water in the air to form acidic compounds.