Factors Affecting Vapour Pressure
Vapour Pressure of the liquid depends on the various factor discussed below:
- Nature of Liquid: Intermolecular forces between the atoms of the liquid explain the nature of the liquid. Vapour Pressure of the liquid changes according to different types of liquids.
- Effect of Temperature: With the increase in temperature of the liquid, the kinetic energy of the atoms of the liquid also increases. Now, the liquid molecules with high kinetic energy are less likely to escape thus, the vapour pressure of the liquid increases. Hence we can say that vapour pressure is directly proportional to temperature.
- Concentration of Solute: The existence of a solute in the liquid will significantly reduce the vapour pressure. And this fall in vapour pressure also differs with respect to the concentration of solute.
Vapour Pressure
Vapour pressure is the force exerted by a liquid’s (or solid’s) vapour above the surface of the liquid. At a particular temperature and thermodynamic equilibrium, this pressure is formed in a closed container. The rate of liquid evaporation is controlled by the equilibrium vapour pressure. The vapour pressure increases with increasing temperature. When atmospheric pressure and vapour pressure are equal, a liquid is said to have reached its boiling point.