When a hydronium ion concentration equals 1 × moles per liter, what is the pH of the solution? Is the solution acidic or basic?

Question

When a hydronium ion concentration equals 1 ×  moles per liter, what is the pH of the solution? Is the solution acidic or basic?

Quizplus · Accepted Answer

A hydrogen ion concentration of 1 × 10^-11 moles per liter corresponds to a pH of 11, since pH = -log(H+).
Therefore, a hydronium ion concentration of 1 × 10^-11 moles per liter corresponds to a pH of (14-11) or 3.
However, the question is asking for the pH of a solution with a hydronium concentration of 1 × 10^-11 moles per liter, which is not possible since the concentration cannot be less than or equal to 1 × 10^-7 moles per liter for a solution to be acidic. As a result, the answer would be A, and the solution is acidic.

When a Hydronium Ion Concentration Equals 1 × Moles