`0.15`g of a subatance dissolved in `15`g of solvent boiled at a temperature higher at `0.216^(@)`than that of the pure solvent. Calculate the molecular weight of the substance. Molal elecation constant for the solvent is `2.16^(@)C`

Options

A. 216
B. 100
C. 178
D. None of these

Answer

B

Explanation

Here is given that
`w=0.15g,DeltaT_b==0.216^@C`
`W=15g,K_b=2.16^@C` m = ?
Substituting values in the expression ,
`m=(1000xxK_bxxw)/(DeltaT_bxxW)`
`m=(1000xx2.16xx0.15)/(0.216xx15)=100`