Practice question

Question

A sample of benzene, contaminated with a non-volatile and non-ionic solute, boils at 0.31°C higher than that of pure benzene. The molality of the solute in the contaminated solution is ______ (round off to two decimal places). Given: Gas constant = 8.314 J K ⁻¹ mol ⁻¹ Molecular weight of benzene is 78.11 g mol ⁻¹ Normal boiling point of benzene is 80.1°C Enthalpy of vaporization of benzene is 30.76 kJ mol ⁻¹ (NAT)