Physical Means of Separating Mixtures

Evaporation
Another way of separating mixtures is through evaporation, or the process by which a liquid changes into vapor or gas. When the temperature of a liquid is raised to boiling point, the liquid becomes vapor. In a salt solution, the solid form of salt can be recovered by boiling the solution to dryness. The water in the solution evaporates, while the granules of salt remain in the container. This process is used when making rock salt from seawater.

The principle of evaporation is also applied in preserving fish by drying. Water is present in the body of the fish, and the fish is exposed under the sun to remove its water content. The water in the wet fish evaporates and the remaining substance is dried up due to heat.