Odpowiedź:
pH = 2,87; pOH = 11,13
Wyjaśnienie:
Dane: Szukane:
Ck=0,1mol/dm³ pH, pOH = ?
K = 1,8*10⁻⁵
CH₃COOH =[H₂O]= CH₃COO⁻ + H⁺
K = [CH₃COO⁻] * [H⁺] / [CH₃COOH]
[CH₃COO⁻] = [H⁺]
[CH₃COOH} = Ck - [H⁺]
Kwas octowy to słaby elektrolit, C/K > 400, czyli [CH₃COOH] ≅ Ck
K = [H⁺]² / Ck
[H⁺] = √K*Ck
[H⁺] = √1,8*10⁻⁵*10⁻¹
[H⁺] = 1,34*10⁻³
pH = -log[H⁺] = -log( 1,34*10⁻³)
pH = 2,87
pH + pOH = 14
pOH = 14 - 2,87
pOH = 11,13
