Evaporation of Common Salt Solution

Why does evaporation of a common salt solution leave common salt behind?

What happens to the salt molecules and water molecules during the evaporation process?

Answer:

Evaporation of a common salt solution leaves behind common salt inside the evaporating dish because salt molecules have a higher boiling point than water and do not evaporate easily, while water molecules gain enough energy to escape as water vapor.

When a common salt solution is heated and undergoes evaporation, the water molecules in the solution gain enough energy to escape into the air as water vapor. However, the salt molecules (sodium chloride) are left behind in the evaporating dish because they have a higher boiling point than water and do not evaporate easily.

As the water evaporates, the concentration of salt in the remaining solution increases, eventually reaching a point where the salt begins to crystallize and solidify. This process results in common salt being left behind in the evaporating dish.