Acetic acid as a pure substance contains no water, so pure acetic acid has by definition no pH.
pH=−log([H3O+)
A solution of acetic acid in water does have a pH, but it depends on the temperature and the concentration of the dissolved substance.
Acetic acid is a weak acid, so the pH of 0.1 M acetic acid would be higher than the pH of 0.1 M hydrochloric acid. Acetic acid with a molar concentration of 0.1 M has a pH of 2.87, and 0.0001 M of acetic acid has a pH of 4.3.
