On the pH of Potassium Acetate in Water

On the pH of Potassium Acetate in Water. Potassium acetate is the salt of acetic acid and potassium hydroxide.

When potassium acetate is dissolved in water, its acetate ion ($CH_3COO ^ - $) will undergo hydrolysis. In water, hydrogen ions ($H ^ + $) and hydroxide ions ($OH ^ - $) are weakly ionized. Acetate ions combine with hydrogen ions ionized from water to form acetic acid ($CH_3COOH $). The ionic equation for this reaction is: $CH_3COO ^ - + H_2O\ rightleftharpoons CH_3COOH + OH ^ - $.

Due to the combination of acetate ions with hydrogen ions, the ionization balance of water is moved forward, resulting in an increase in the concentration of hydroxide ions in the solution and a relative decrease in the concentration of hydrogen ions. Therefore, the solution of potassium acetate in water is alkaline, and its pH (pH) is greater than 7. This is based on the principle of salt hydrolysis. It can be seen that salts in water have a specific pH due to the interaction between ions and water. This is an important phenomenon and knowledge in the chemical aqueous solution system.