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When 20 g of naphthoic acid (C(11)H(8)O(...

When `20 g` of naphthoic acid `(C_(11)H_(8)O_(2))` is dissolved in `50 g` of benzene `(K_(f)=1.72 K kg mol^(-1))`, a freezing point depression of `2 K` is observed. The Van't Hoff factor (i) is

A

0.5

B

1

C

2

D

3

Text Solution

Verified by Experts

The correct Answer is:
A
`DeltaT_(f)=i xx K_(f) xx m (Mw_(2)=172)`
or `2=i xx 1.72 xx(20/172) xx (1/50) xx 1000`
or `i=0.5`
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