Sebanyak 25 ml larutan ch3cooh 0,3 m (ka= 1x10-5) dicampur dgn 25 nl. Larutan naoh 0,1 m, maka harga ph larutan yg terjadi

CH3COOH + NaOH → CH3COONa + H2O

→ CH3COOH
m = 25 x 0,3 = 7,5
r = 2,5
s = 5

→ NaOH
m = 25 x 0,1 = 2,5
r = 2,5
s = -

→ CH3COONa
m = -
r = 2,5
s = 2,5

→ H2O
m = -
r = 2,5
s = 2,5

[H+] = Ka (sisa asam / garam)
[H+] = 10^-5 (5 / 2,5)
[H+] = 10^-5 x 2

pH = -log [H+]
pH = -log 2 x 10^-5
pH = 5 - log2