The correct option is B 0.229
We have, ΔT=Kf×molality×(1+α)For acetic acid:CH3COOH↔CH3COO−+H+
1 0 0
1−α α α
Given, α=0.23;
Also, molality=mole of acetic acidweight of water in kg
=(3×10−3×103){60×(500×0.997)103}=0.10ΔT=Kf×molality×(1+α)=1.86×0.1×1.23=0.229(B)