CH3COOH + NaOH
CH
3COONa + H
2O
After adding 25 ml of NaOH volume of mixture = 50 + 25 = 75 ml
Initially,
Number of millimole of NaOH = 25
0.1 = 2.5 mm
Number of millimole of CH3COOH = 50
0.1 = 5 mm
After nutrilisation,
Millimole of NaOH = 0
Millimole of CH3COOH = 5
2.5 = 2.5 mm
Millimole of CH3COONa = 2.5
After nutrilisation,
Concentration of CH3COOH =
[CH3COOH]=755−2.5=301
Concentration of CH3COONa =
[CH3COONa]=752.5=301
PH=PKa+log[CH3COOH][CH3COONa]
=4.76+log301301
=4.76+log(1)
=4.76+0
=4.76×10−2 
