Textbook $3\mathrm{.}16$ revised:

When pure $Cl2$ gas is bubbled into water, it hydrolyzes to form hypochlorous acid $(HOCl)$ and hypochlorite ion $(OCl-),$ with a pKa of $7\mathrm{.}6($Table $3\mathrm{.}2).$ Assuming KH is $0\mathrm{.}086\frac{M}{a}tm,$ what is the concentration of HOCl at $pH6?$