question_answer

Pure benzene freezes at  A solution of 0.223    g    of    phenylacetic    acid   in 4.4 g of benzene    freezes at  From this observation, one can conclude that     

A)      phenylacetic acid exists as such in benzene

B)   phenylacetic acid undergoes partial ionisation in benzene

C)  phenylacetic acid undergoes complete ionisation in benzene

D)  phenylacetic acid dimerises in benzene

Correct Answer: D

Solution :

                 Depression in freezing point,  (where m = molality)                                            Theoretical Actual                                                   Association will take place. Thus, it can be said that phenylacetic acid dimerises in benzene.