The freezing point depression of 0.1 molal solution of acetic acid in benzene is 0.256 K , `K_(f)` for benzene is 5.12 K Kg `mol^(-1)`. What conclusion can you draw about the molecular state of acetic acid in benzence ?

Explanation

`Delta T_(f) = K_(f) xx m`
` = 5.12 xx 0.1 = 0.512 K`
Observed `Delta T_(f) = 0.256 K`
Van.t Hoff factor , `I =("Observed freezing point depression")/("Calculated freezing freezing point depression")`
` = (0.256)/(0.512) = 0.5`
Since .i. is less than one , this means that `CH_(3)COOH` undergoes assocition in benzene. The value 0.5 indicates that the number of particle become half and therefore , `CH_(3)COOH` dimerises in benzene.