equation for the acetic acid reacts with the concentrated sodium hydroxide solution
Acetic acid (CH3COOH) is acid and Sodium hydroxide (NaOH) is base or alkali.
Acetic acid neutralises sodium hydroxide base to form salt of sodium acetate and this reaction also generate water.
CH3COOH (aq) + NaOH(aq) CH3COO-Na (aq) + H2O(aq)
This type of reaction is called as acid-base neutralisation reaction.