The chemical equation for the reaction between acetic acid (CH3COOH) and potassium hydroxide (KOH) is:

CH3COOH(aq) + KOH(aq) → CH3COOK(aq) + H2O(l)

This reaction is a neutralization reaction, which occurs when an acid and a base react to form a salt and water. In this case, the salt formed is potassium acetate (CH3COOK), and the water is a byproduct of the reaction.