Explanation:
Ionic product of water, Kw
[tex]Kw = [OH {}^{ - } ][H _{3} O {}^{ + } ] \\ 1.0 \times {10}^{ - 14} = (1 \times {10}^{ - 11} )[H _{3} O {}^{ + } ] \\ [H _{3} O {}^{ + } ] = \frac{(1.0 \times {10}^{ - 14}) }{(1 \times 10 {}^{ - 11}) } \\ ][H _{3} O {}^{ + } ] = 0.001 \: M[/tex]
