Vapour pressure of solution of solids in liquids
- Solution of salt, sugar or glucose dissolved in water is solutions of solids in liquids.
- Similarly iodine and sulphur dissolved in carbon disulphide are also solutions of solids in liquids
- Addition of anon-volatile solute to a solvent togive a solution results in the exertion of the vapourpressure of the solution uniquely from the solvent.
- This vapour pressure is lower than the vapour pressure of the pure solvent at a given temperature.
- The surface of the solution is occupied by both solute andsolvent molecules which results in the reduction of the surface for the solvent molecules. As a result the apparent number ofsolvent molecules escaping from the surface is reduced. This in turn reduces the vapour pressure.
- The reduction of vapour pressure of solvent depends on thequantity of non-volatile solute present in the solution not on its nature.
