Question

The molal elevation constant for water is `0.56 K kg mol^(-1)`. Calculate the boiling point of a solution made by dissolving 6.0g of urea `(NH_(2)CONH_(2))` in 200g of water.

Answer 1

`DeltaT=(100K_(b)xxw)/(mxxW)`
Given, `K_(b)=0.56"K kg mol"^(-1),w=6.0g,W=200g,m=60`
`DeltaT=(1000xx0.56xx6.0)/(200xx60)=0.28^(@)C`
Thus, the boiling point of solution = b.pt of water `+ Delta T`
`= (100^(@)C+0.28^(@)C)=100.28^(@)C`.