The reaction between calcium hydroxide and nitric acid is an acid-base reaction, also known as a neutralization reaction. In this type of reaction, an acid (nitric acid in this case) reacts with a base (calcium hydroxide in this case) to form a salt (calcium nitrate) and water. Here is the balanced chemical equation for this reaction:

Ca(OH)2 + 2HNO3 → Ca(NO3)2 + 2H2O

In this equation, calcium hydroxide (Ca(OH)2) and nitric acid (HNO3) are the reactants, while calcium nitrate (Ca(NO3)2) and water (H2O) are the products.