Answer
(a) $[H_3O^+] = 2.8 \times 10^{- 9}M$
(b) $[H_3O^+] = 5.9 \times 10^{- 12}M$
(c) $[H_3O^+] = 1.3 \times 10^{- 3}M$
(d) $[H_3O^+] = 6.0 \times 10^{- 2}M$
Work Step by Step
We use the equation for the concentration of $H_3O^+$ to find:
(a)
$[H_3O^+] = 10^{-pH}$
$[H_3O^+] = 10^{- 8.55}$
$[H_3O^+] = 2.8 \times 10^{- 9}M$
(b)
$[H_3O^+] = 10^{-pH}$
$[H_3O^+] = 10^{- 11.23}$
$[H_3O^+] = 5.9 \times 10^{- 12}M$
(c)
$[H_3O^+] = 10^{-pH}$
$[H_3O^+] = 10^{- 2.87}$
$[H_3O^+] = 1.3 \times 10^{- 3}M$
(d)
$[H_3O^+] = 10^{-pH}$
$[H_3O^+] = 10^{- 1.22}$
$[H_3O^+] = 6.0 \times 10^{- 2}M$
