Why is acetic acid a weak acid?

1 Answer
Dec 26, 2015

It ionizes to a small extent in water to form a low concentration of #H^+# ions (or #H_3O^+#) in solution.

In the reversible chemical equation, #CH_3COOH->H_(aq)^+ +CH_3COO_(aq)^-#,
the equilibrium lies far to the left and hence the #K_a# value is very small.