Question

Diketahui campuran 100mL larutan CH3COOH 0,1M dan 1000 mL larutan CH3COONa 0,1 M ( Ka=1,8×10^-5) tentukan ph campuran

Answer 1

Mmol CH3COOH = 100 x 0,1 = 10 mmol
mmol CH3COONa = 1000 x 0,1 = 100 mmol
Ka = 1,8 x10⁻⁵

[H+] = Ka  x mol asam / mol garam
[H+] = 1,8 x10⁻⁵ x 10/100
[H+] = 1,8 x10⁻⁶
pH = - log 1,8 x10⁻⁶
pH = 6 - log 1,8
pH = 6 - 0,26 = 5,74