Answer
See the answer below.
Work Step by Step
Net ionic reaction:
$CH_3CH_2CO_2^-+H_2O\leftrightarrow CH_3CH_2CO_2H+OH^-$
$K=[CH_3CH_2CO_2H][OH^-]/[CH_3CH_2CO_2^-]=K_w/K_a$
$10^{-14}/1.34\cdot10^{-5}=x^2/(0.10-x)$
$x=8.64\cdot10^{-6}\ M=[CH_3CH_2CO_2H]=[OH^-]$
$[CH_3CH_2CO_2^-]\approx 0.10\ M$
$[H_3O^+]=K_w/[OH^-]=1.16\cdot10^{-9}\ M$
