The reaction between potassium hydroxide (KOH) and nitric acid (HNO3) results in the formation of potassium nitrate (KNO3) and water (H2O). The chemical equation for this reaction is:

KOH + HNO3 → KNO3 + H2O

In this reaction, potassium hydroxide acts as a base, while nitric acid acts as an acid. The reaction is a neutralization reaction, where the base and acid react to form a salt (potassium nitrate) and water.