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The melting point of phenol is 40^(@)C. ...

The melting point of phenol is `40^(@)C`. A solution containting `0.172 g`acetanilide `(C_(8)H_(9)OH)` in `12.54 g`.phenol freezes at `39.25^(@)C`. Calculate the freezing point constant and the latent heat of fusion of phenol.

Text Solution

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`DeltaT_(f)=40-39.25=0.75`,`Mw_(2)=135`
`K_(f)=(DeltaT_(f))/(m)=(0.75)/((0.172)/(135)xx(1000)/(12.54))=0.738 K kg m^(-1)`
`=7.38 per 100 g`
`T_(f)=273+40=313 K`
`K_(f)=(RT_(f)^(2))/(lxx1000)=(2xx(313)^(2))/(lxx1000)`
`l = (2xx(313)^(2))/(K_(f)xx1000)=(2xx(313)^(2))/(7.38xx1000)=26.5 cal g^(-1)`
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