The freezing point of solution containing `0.2 g` of acetic acid in `20.0 g` of benzene is lowered by `0.45^(@)C`. Calculate the degree of association of acetic acid in benzene.
`(K_(f)=5.12 K^(@) mol^(-1) kg^(-1))`

Answer

0.945

Explanation

Acetic acid -B, Benzene-A
For acetic acid,` "n=2"`
`Delta"T"_("f")="i"xx("K"_("f")xx"W"_("B")xx1000)/("m"_("B")xx"W"_("A")("g"))" "0.45xx"i"xx(5.12xx0.2xx1000)/(60xx20)`
`"i=0.527"`
`1-(alpha)/(2)=1`
`1-(alpha)/(2)=0.527`
`alpha=0.945`
`alpha=94.5%`