Chapter 8, Problem 51E

A solution contains $1.0\text{ × }{10}^{-6}M\text{ HOCl}$ and an unknown concentration of $\text{KOCl}\text{.}$ If the pH of the solutionis $7.20,$ calculate the $\text{KOCl}\text{.}$ concentration. (Hint: The contribution of water to the $\left[{\text{H}}^{+}\right]$ cannot be ignored.)