HI is a strong acid, which means it completely dissociates in water to produce H+ ions and I- ions. Therefore, the concentration of H+ ions in a 0.0320 M solution of HI is also 0.0320 M.
pH is defined as the negative logarithm of the concentration of H+ ions:
pH = -log[H+]
Substituting the given concentration:
pH = -log(0.0320) = 1.495
Therefore, the pH of a 0.0320 M solution of HI is 1.495.