The reaction between nitric acid (HNO3) and sodium hydroxide (NaOH) is an acid-base reaction, also known as a neutralization reaction. It can be represented by the following equation:

HNO3 + NaOH → NaNO3 + H2O

In this reaction, nitric acid (HNO3) donates a hydrogen ion (H+) to sodium hydroxide (NaOH), resulting in the formation of water (H2O). The remaining ions, sodium (Na+) and nitrate (NO3-), combine to form sodium nitrate (NaNO3), which is a salt.

This reaction is an example of a strong acid (HNO3) reacting with a strong base (NaOH), which results in the formation of a salt (NaNO3) and water (H2O). The salt produced is neutral, meaning that it does not exhibit any acidic or basic properties.