20 mL of 0.1 M NaOH is added to 50 mL of 0.1 M acetic acid solution. The pH of the resulting solution is ________ ×10-2 (Nearest integer)
Given: pKa(CH3COOH) = 4.76
log 2 = 0.30
log 3 = 0.48 [2023]
(458)
NaOH + CH3COOH→CH3COONa+H2O
0.1 M, 20 ml 0.1 M, 50 ml
Millimole=0.1×20=2, 0.1×50=5
L.R.=NaOH
So 0 5-2=(3) (2)
So resultant solution is an acidic buffer solution
So pH=pKa+log(saltacid)
pH=4.76+log23
pH=4.76+(-0.18)=4.58=458×10-2