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12.2 g of benzoic acid (Mw=122) in 100 g...

`12.2 g` of benzoic acid `(Mw=122)` in `100 g` water has elevation in boiling point of `0.27.K_(b)=0.54 K kg mol^(-1)`.If there is `100%` polymerization, the number of molecules of benzoic acid in associated state is

A

2

B

1

C

3

D

4

Text Solution

Verified by Experts

The correct Answer is:
A
`DeltaT_(b)=iK_(b)m`
`0.27 = I xx 0.54 xx(12.2/122)xx(1000/100)`
or `i=0.5`
Therefore, benzene associated as dimer, i.e.,2.
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