Nitric acid is neutralised by a base, such as sodium hydroxide, to form a salt, such as sodium nitrate, and water.

The chemical equation for the reaction is:

HNO3 + NaOH → NaNO3 + H2O

In this reaction, the hydrogen ion (H+) from the nitric acid reacts with the hydroxide ion (OH-) from the sodium hydroxide to form water (H2O). The nitrate ion (NO3-) from the nitric acid and the sodium ion (Na+) from the sodium hydroxide combine to form sodium nitrate (NaNO3).