The reaction between acetic acid and potassium hydroxide
Acetic acid is a weak acid with mild properties and decomposes in the middle of water. Potassium hydroxide, a strong base, is completely dissociated into potassium ions and hydroxide ions in contact with water.

When acetic acid and potassium hydroxide meet, the two neutralize. The hydrogen ion of acetic acid combines with the hydroxide ion of potassium hydroxide to form water. The residual group of acetic acid combines with the potassium ion to form potassium acetate.

The chemical equation for the reaction is: $CH_3COOH + KOH\ longrightarrow CH_3COOK + H_2O $. During this reaction, the acid and alkali properties of the solution gradually change. Initially, if the amount of acetic acid is large, the solution is acidic; with the gradual addition of potassium hydroxide, hydrogen ions and hydroxide ions are neutralized, and the acidity of the solution gradually weakens. When the two react completely according to the stoichiometric number, the solution is neutral. If there is an excess of potassium hydroxide, the solution turns to alkaline.

This reaction is useful in chemical experiments, industrial production and daily life. In the laboratory, such neutralization reactions are often used to determine the concentration of substances; in industry, it can be used to prepare salts such as potassium acetate; in life, it can also be used as a means to adjust the acidity and alkalinity of solutions.