Answer
(a) $[H_3O^+] = 3.8 \times 10^{- 3}M$
(b)$[H_3O^+] = 6.16 \times 10^{- 12}M$
(c)$[H_3O^+] = 1.09 \times 10^{- 7}M$
(d)$[H_3O^+] = 1 \times 10^{- 15}M$
Work Step by Step
(a)
$[H^+] = 10^{-pH}$
$[H^+] = 10^{- 2.42}$
$[H^+] = 3.8 \times 10^{- 3}$
(b)
$[H^+] = 10^{-pH}$
$[H^+] = 10^{- 11.21}$
$[H^+] = 6.16 \times 10^{- 12}$
(c)
$[H^+] = 10^{-pH}$
$[H^+] = 10^{- 6.96}$
$[H^+] = 1.09 \times 10^{- 7}$
(d)
$[H^+] = 10^{-pH}$
$[H^+] = 10^{- 15}$
$[H^+] = 1 \times 10^{- 15}$
