Question

Calculate the pH when $50mL$ of $0.1MNaOH$ is added to $50mL$ of $0.1M$ acetic acid solution. $(Kw=1.00\times {10}^{-14})$

(Answer to closest integer)

Answer 1

${CH}_{3}COOH\rightleftharpoons {C{H}_{3}COO}^{-}+H^{+}$

$\left[{CH}_3{COO}^{-}\right]=\frac{50}{1000}=0.05M$

$K_b=\frac{\left[{CH}_{3}COOH\right]\left[{OH}^{-}\right]}{\left[{CH}_{3}COOH\right]}=\frac{x^2}{0.05}=5.6\times {10}^{-10}$

$x={5.29\times 10}^{-6}$

$pOH=5.27$

$pH=14-pOH=8.72$