Why does sodium benzoate react with hydrochloric acid?

Answer 1

Sodium benzoate is a salt of a weak acid (benzoic acid). In water, sodium benzoate hydrolyses to form a strong base (sodium hydroxide) and benzoinc acid. This is an equilibrium reaction. Benzoic acid being a weak acid is only partially ionized in water whilst sodium hydroxide is fully ionoized. The resultant solution is therefore alkaline since the concentration of hydroxyl ions is greater than the concentration of hydrogen ions. The addittion of hydrochloric acid results in an acid base reaction formating a salt (sodium chloride). Since the addition of hydrochloric acid removes the sodium hydroxide, it forces the equilibrium to the right forming more benzoic acid which is precipitated.

Answer 2

Sodium benzoate reacts with hydrochloric acid to form benzoic acid and sodium chloride. This reaction is a typical acid-base reaction where the hydrogen ions from the hydrochloric acid replace the sodium ions in sodium benzoate, forming a new compound.

Answer 3

A solid forms