sebanyak 100 mL larutan CH3COOH 0,2 M dicampurkan dengan 100 mL larutan NaOH 0,2 M. jika Ka CH3COOH = 1 x 10⁻⁵ , maka pH larutan setelah dicampur adalah... a. 2

[tex]\displaystyle \underset{20\text{mmol}}{\underset{20\text{mmol}}{\text{CH}_3\text{COOH}_{(aq)}}}+\underset{20\text{mmol}}{\underset{20\,\text{mmol}}{\text{NaOH}_{(aq)}}}\to\underset{20\text{mmol}}{\underset{}{\text{CH}_3\text{COONa}_{(aq)}}}+\text{H}_2\text{O}_{(l)}\\\\\\\left[\text{OH}^-\right]=\sqrt{\frac{K_w}{K_a}\left[\text{CH}_3\text{COO}^-\right]}\\\left[\text{OH}^-\right]=\sqrt{\frac{10^{-14}}{10^{-5}}\cdot\frac{20}{200}}\\\left[\text{OH}^-\right]=\sqrt{10^{-9}\cdot0,1}[/tex]
[tex]\displaystyle \left[\text{OH}^-\right]=\sqrt{10^{-10}}\\\left[\text{OH}^-\right]=10^{-5}\\\\\text{pOH}=-\log[\text{OH}^-]\\\text{pOH}=-\log10^{-5}\\\text{pOH}=5\\\\\text{pH}=14-\text{pOH}\\\text{pH}=14-5\\\boxed{\boxed{\text{pH}=9}}[/tex]