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A certain solution of 1 m benzoic acid i...

A certain solution of `1 m` benzoic acid in benzene has a freezing point of `3.1^(@)C` and a normal boiling point of `82.6 ^(@)C`. The freezing point of benzene is `5.5^(@)C`. And its boiling point is `80.1^(@)C`. Analyze the state of the solute (benzoic acid ) at two temperature and comment .

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Case I
Calculate Van't Hoff factor in two cases:
`i=DeltaT_(f)/(K_(f)xxm)=(5.5-3.1)/(5.12xx1)=0.469`
`:.ilt1.`
So benzoic acid associates in bezene at low temperature since `i~~0.5`, so it forms dimer.
Case II
`i=DeltaT_(f)/(K_(f)xxm)=(82.6-80.1)/(2.53xx1)=0.99`
`ilt1` and `i~~1`.
so benzoic acid neither associates nor dissociates at high temperature.
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