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1.00 g of a non-electrolyte dissolved in...

1.00 g of a non-electrolyte dissolved in 50.5g of benzene lowered its freezing point by 0.40K. The freezing point depression constant of benzene is `"5.12K.kg mol"^(-1)`. Find the molecular mass of the solute.

Text Solution

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`DeltaT_(f)=0.40K`
`K_(f)="5.12 kg mol"^(-1)`
`W_(2)=1g`
`W_(1)="50.5 gm "=(50.5)/(1000)kg`
`M_(2)=(K_(f))/(DeltaT_(f))xx(W_(2))/(W_(1))`
`therefore" "M_(2)=(5.12)/(0.40)xx(1)/(50.5)xx1000`
`="2.56 g mol"^(-1)`
Thus, the molecule mass of the solute `=" 256 g mol"^(-1)`.
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