The depression in freezing point of water observed for the same amount of acetic acid, trichloroacetic acid and trifluoroacetic acid increases in the order given above. Explain briefly.
When strongly electron withdrawing groups are present on alpha C atom of acetic acid, the acid strength and the degree of dissociation increases. This increases the vant Hoff factor i and the depression in the freezing point. Trifluoroacetic is most acidic because fluorine is most electron withdrawing in nature. Hence, trifluoroacetic acid has maximum depression in the freezing point.
