Final answer:
The concentration of hydrogen ion in a 0.30 M solution of acetic acid would be less than 0.30 M because acetic acid is a weak acid and does not fully dissociate in water.
Step-by-step explanation:
The concentration of hydrogen ion ([H+]) in a 0.30 M solution of acetic acid would be less than 0.30 M because acetic acid is a weak acid and does not ionize completely in water. The extent of ionization for weak acids is generally less than 10%, so the majority of the acetic acid molecules remain undissociated. For example, a 0.10 M solution of acetic acid is only about 1.3% ionized, indicating that equilibrium strongly favors the reactants. Therefore, in a 0.30 M acetic acid solution, the concentration of ionized hydrogen ions will be significantly less than the initial concentration of acetic acid.