Answer
(a)$[OH^-] = 4.21 \times 10^{- 10}M$
(b)$[OH^-] = 1.2 \times 10^{- 6}M$
(c)$[OH^-] = 7.77 \times 10^{- 4}M$
(d)$[OH^-] = 1.75 \times 10^{- 12}M$
Work Step by Step
(a)
$[H^+] * [OH^-] = Kw = 5.48 \times 10^{-14}$
$ 1.3 \times 10^{- 4} * [OH^-] = 5.48 \times 10^{-14}$
$[OH^-] = \frac{5.48 \times 10^{-14}}{ 1.3 \times 10^{- 4}}$
$[OH^-] = 4.21 \times 10^{- 10}$
(b)
$[H^+] * [OH^-] = Kw = 5.48 \times 10^{-14}$
$ 4.55 \times 10^{- 8} * [OH^-] = 5.48 \times 10^{-14}$
$[OH^-] = \frac{5.48 \times 10^{-14}}{ 4.55 \times 10^{- 8}}$
$[OH^-] = 1.2 \times 10^{- 6}$
(c)
$[H^+] * [OH^-] = Kw = 5.48 \times 10^{-14}$
$ 7.05 \times 10^{- 11} * [OH^-] = 5.48 \times 10^{-14}$
$[OH^-] = \frac{5.48 \times 10^{-14}}{ 7.05 \times 10^{- 11}}$
$[OH^-] = 7.77 \times 10^{- 4}$
(d)
$[H^+] * [OH^-] = Kw = 5.48 \times 10^{-14}$
$ 3.13 \times 10^{- 2} * [OH^-] = 5.48 \times 10^{-14}$
$[OH^-] = \frac{5.48 \times 10^{-14}}{ 3.13 \times 10^{- 2}}$
$[OH^-] = 1.75 \times 10^{- 12}$
