Answer
$[H_3O^+] = 0.1M$
$[OH^-] = 1 \times 10^{- 13}M$
This solution is acidic.
Work Step by Step
$[H_3O^+] = 10^{-pH}$
$[H_3O^+] = 10^{- 1}$
$[H_3O^+] = 0.1M$
$[H_3O^+] * [OH^-] = Kw = 10^{-14}$
$ 0.1 * [OH^-] = 10^{-14}$
$[OH^-] = \frac{10^{-14}}{0.1}$
$[OH^-] = 1 \times 10^{- 13}M$
$[H_3O^+] > [OH^-]$ : Acidic solution.
Assuming $25 ^{\circ} C$: pH < 7: Acidic solution.
