jika dua larutan masing masing mengandung 25 mL NaOH 0,2 M dan 25 mL CH3COOH 0,2 M dengan KaCH3COOH =10-5 di campurkan ,besarnya pH adalah

25 mL NaOH 0,2 M + 25 mL CH3COOH 0,2 M
Ka = 10^-5

pH campuran ... ?

*n NaOH = M × V
n NaOH = 0,2 × 25 mL
n NaOH = 5 mmol

*n CH3COOH = M × V
n CH3COOH = 0,2 × 25 mL
n CH3COOH = 5 mmol

#Reaksi
... NaOH + CH3COOH => CH3COONa + H2O
M : . 5 ............... 5
R : . 5 ............... 5
________________---
S : . --- .............. --- ..................... 5 ............... 5

M = n / V total
M = 5 / (25 + 25)
M = 5 / 50
M = 0,1

Garam CH3COONa bersifat basa
[OH^-] = √( Kw/Ka × M )
[OH^-] = √( 10^-14/10^-5 × 0,1 )
[OH^-] = √( 10^-9 × 0,1 )
[OH^-] = √( 10^-10 )
[OH^-] = 10^-5

pOH = - log [OH^-]
pOH = - log 10^-5
pOH = 5

pH = 14 - pOH
pH = 14 - 5
pH = 9