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0.70 g of an organic compound when disso...

0.70 g of an organic compound when dissolved in 32 g of acetone produces an elevation of 0.25°C in the boiling point. Calculate the molecular mass of organic compound. `(K_(b)" for acetone" = 1.72" K kg mol"^(-1))`.

Text Solution

Verified by Experts

Given : Wt. Of the solute (w) = 0.70g
Wt. of the solvent (W) = 32g
Elevation of boiling point `(DeltaT_(b))=0.25^(@)C`
`K_(b)=1.72K kgmol^(-1)`
The relation of elevation of boiling point and molecular mass is :
`m=(1000xxK_(b)xxw)/(WxxDeltaT_(b))`
`=(1000xx1.72xx0.70)/(32xx0.25)`
= 150.5g
Thus, the molecular mass of the organic compound is 150.5g.
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