Chapter 13, Problem 13.109SP

Interpretation Introduction

Interpretation:

The mole fraction of cyclopentane, ${\text{χ}}_{\text{cyclopentane}}$ needs to be determined, if the vapor pressure of cyclopentane at 30.0°C is 385 mmHg, vapor pressure of cyclohexane is 122 mmHg and the vapor pressure of mixture is 212 mmHg at 30.0°C.

Concept introduction:

Colligative properties are the properties that depend on the number of particles present in the solution. Elevation in boiling point, depression in freezing point, lowering in vapor pressure and osmotic pressure are some common examples of colligative properties. Vapor pressure is the pressure that is exerted by vapor on the liquid surface in a closed system when the system is in thermodynamic equilibrium.

When a non-volatile solute is dissolved in a solvent to get the solution, the vapor pressure decreases for the solution and it can be calculated with the help of Raoult’s law. The law states that the vapor pressure of the solution is the product of a mole fraction of the solvent and vapor pressure of the pure solvent.