Question

Elevation in boiling point of an aqueous urea solution is 0.52.Hence mole fraction of urea in this solution is

Answer 1

Answer:

Mole fraction of urea in this solution is 0.0176.

Explanation:

Expression for elevation in boiling point is given as:

$\Delta T_b=K_b\times m$

$0.52 K=0.52 K kg/mol\times m$

$m=1 mol/kg$

Molality of the urea solution is 1 mol/Kg.

Mass of water = 1kg = 1000 g

Moles of water = $\frac{1000 g}{18 g/mol}=55.55 mol$

Mole fraction of urea:

$\chi_u=\frac{1 mol}{1mol+55.55 mol}=0.0176$