Question

A mixture of camphor and ${\text{KCl}}$ can be separated by :
A.Evaporation
B.Sublimation
C.Filtration
D.Decantation

Answer 1

Hint: Camphor scientifically known as Cinnamomum Camphor. It is a combustible translucent white solid which has a piquant smell and sour taste. Camphor belongs to a group of organic compounds defined as terpenoid ketones. Potassium Chloride is an important metal halide. Which is an essential electrolyte source for our body. Each ${\text{KCl}}$ molecule contains one potassium cation and one chloride anion.

Complete step by step solution:
Camphor is a white waxy solid which melts about ${178^0}{\text{C}} - {179^0}{\text{C}}$. Whereas ${\text{KCl}}$ is odourless white crystalline solid with a melting point of ${770^0}{\text{C}}$.
Usually we know that when we heat a solid they melt first to become a liquid. On further heating liquid boils and enters into vapor phase. But some solid substances will directly change into gases from solid state on heating. For example camphor, Naphthalene such substances are called sublime. So this process of conversion is known as sublimation.
Sublimation occurs because we know that all substances are made of atoms and molecules. These particles are held together by a force of attraction. If the force of attraction between the particles is weak then the particles can separate easily. So in camphor the molecules are held together by weaker force so it can simply evaporate on heating without melting. In camphor the molecules are held together by weak attractive force , which means that even at moderate temperature the molecule of camphor can escape and spread everywhere.
Here given is camphor and ${\text{KCl}}$ mixture, in which camphor is a solid sublimate component and ${\text{KCl}}$ is a non sublimate component. To separate these mixtures we can use the sublimation process. The vapor s of camphor can be collected and cooled down.

Hence, option B is the correct answer.

Note: The changing of solid directly into vapor s on heating , and vapor s directly into solid on cooling is called sublimation. The solid substance which undergoes sublimation is called sublime. And the solid substance obtained by cooling the vapor is known as sublimate.