The reaction between acetic acid and potassium hydroxide
Acetic acid is mild in nature and is a weak acid. It is separated and hydrolyzed in the middle of water. Potassium hydroxide, a strong base, is completely dissociated into potassium ions and hydroxide ions in contact with water. When the two meet, it is a neutralization reaction.

The chemical equation of the reaction is: $CH_ {3} COOH + KOH\ longrightarrow CH_ {3} COOK + H_ {2} O $. In this case, the hydrogen ion of acetic acid combines with the hydroxide ion of potassium hydroxide to form water. Acetate ions and potassium ions coexist in the solution to form potassium acetate.

Looking at the microscopic scale, only a small amount of acetic acid in the solution dissociates into hydrogen ions and acetate ions. When potassium hydroxide is added, hydroxide ions quickly combine with hydrogen ions dissociated by acetic acid, which prompts acetic acid to follow the principle of Le Chatelier and continue to dissociate to replenish the consumed hydrogen ions until the reaction is complete.

In terms of macroscopic phenomena, if an indicator is added to the reaction system, such as phenolphthalein. Initially, the potassium hydroxide solution is alkaline, and phenolphthalein appears red. With the addition of acetic acid drop by drop, the alkalinity gradually weakens, and the color of the solution gradually lightens. When the reaction is just complete, the solution is neutral and the color of phenolphthalein fades. This reaction is widely used in practical applications. In chemical production, it can be used to prepare potassium acetate; in analytical chemistry, it can be used to neutralize and titrate with acid and base to determine the concentration of acetic acid or