Solution

By the electronegativity rule, only the hydrogen attached to oxygen should be acidic. The equation is

`CH_3COOH + H_2O -> H_3 O^(+) + CH_3COO^(-)`      (1)

Note: To emphasize that only one hydrogen atom is acidic, the formula acetic acid is often written HC₂H₃O₂. You may also find the formulas HAc or HOAc for acetic acid, where Ac^– or OAc^– represents the acetate ion, CH₃COO^–.