Answer
(a) $[H_3O^+] = 4 \times 10^{- 13}M$
(b) $[H_3O^+] = 5.98 \times 10^{- 10}M$
(c) $[H_3O^+] = 1.16 \times 10^{- 12}M$
(d) $[H_3O^+] = 5.71 \times 10^{- 3}M$
Work Step by Step
(a)
$[OH^-] * [H^+] = Kw = 10^{-14}$
$ 2.5 \times 10^{- 2} * [H^+] = 10^{-14}$
$[H^+] = \frac{10^{-14}}{ 2.5 \times 10^{- 2}}$
(b)
$[OH^-] * [H^+] = Kw = 10^{-14}$
$ 1.67 \times 10^{- 5} * [H^+] = 10^{-14}$
$[H^+] = \frac{10^{-14}}{ 1.67 \times 10^{- 5}}$
$[H^+] = 5.98 \times 10^{- 10}$
(c)
$[OH^-] * [H^+] = Kw = 10^{-14}$
$ 8.62 \times 10^{- 3} * [H^+] = 10^{-14}$
$[H^+] = \frac{10^{-14}}{ 8.62 \times 10^{- 3}}$
$[H^+] = 1.16 \times 10^{- 12}$
(d)
$[OH^-] * [H^+] = Kw = 10^{-14}$
$ 1.75 \times 10^{- 12} * [H^+] = 10^{-14}$
$[H^+] = \frac{10^{-14}}{ 1.75 \times 10^{- 12}}$
$[H^+] = 5.71 \times 10^{- 3}$
