Solution | Vapour Pressure of Liquid Solution#
Vapour Pressure#
- The pressure exerted by vapours of a liquid over its liquid surface when the liquid and vapours are in equilibrium is known as vapour pressure.
- Equilibrium means the state where rate of vaporization is equal to rate of condensation.
Image Credit: https://en.wikipedia.org/wiki/Vapor_pressure
Factors affecting vapour pressure#
- Nature of liquid:
- The liquid having strong attraction forces between its molecules will have lower vapour pressure as compared to other liquids.
- Example: water has lower vapour pressure as compared to alcohol due to this reason.
- Temperature:
- On increasing temperature, vapour pressure of liquid will increase and vice-versa.
- Surface Area of liquid:
- Vapour pressure increases with increase in surface area of liquid and vice-versa.
- Purity of solution:
- Vapour pressure of pure liquid will always be greater than the vapour pressure of its solution with a non-volatile solid.
- For example, vapour pressure of pure water is greater than (water + sugar) solution.