Chemistry (4th Edition)

$[OH^-] = 7.14 \times 10^{- 12}M$
1. Since HCl is a strong acid: $[HCl] = [H_3O^+]$ 2. Calculate $[H_3O^+]$ using $[OH^-]$: $[H_3O^+] * [OH^-] = Kw = 10^{-14}$ $1.4 \times 10^{- 3} * [OH^-] = 10^{-14}$ $[OH^-] = \frac{10^{-14}}{ 1.4 \times 10^{- 3}}$ $[OH^-] = 7.14 \times 10^{- 12}$