Question

The best method for the separation of naphthalene and benzoic acid from their mixture is:
A. Sublimation
B. Chromatography
C. Crystallisation
D. Distillation

Answer 1

Hint: Naphthalene is a crystalline white volatile substance with a unique odour that many people associate with mothballs. The compound progressively sublimes (turns from a solid to a gas) at room temperature, releasing a highly combustible vapour. Benzoic acid is a common product in many industrial and home uses, and it is utilised in a variety of daily activities. A carboxyl group is connected to a benzene ring in the structure of benzoic acid.

Complete Step by Step Solution:
Different methods can be used to separate the mixture.
Chromatography is a process for separating different types of mixtures. The mixes are divided into two phases based on their distribution: stationary and mobile phases.
The liquid in which the mixture to be separated is dissolved is referred to as the mobile phase.

Stationary phase: The stationary phase is the phase through which the mobile phase passes.
Crystallisation is a natural occurrence that occurs when materials harden from a liquid or precipitate from a liquid or gas. This method can be carried out using a physical change, such as a change in temperature, or a chemical change, such as acidity.

Distillation is a method of separating two or more components or substances by converting the liquid to vapour and then considerably condensing the vapours back into a liquid state.
Sublimation occurs when a substance moves directly from a solid to a gaseous state without passing through the liquid state. When the particles of a solid absorb enough energy to overcome the forces of attraction between them, the process is known as sublimation. Sublimation is a phase transition that occurs when the phases of solids, liquids, and gases change. A sublimating substance never passes through the liquid state since it transitions immediately from a solid to a gas.

Sublimation is a technique for separating sublimates containing a volatile component from non-sublimate contaminants in mixes.

Benzoic acid is a non-volatile chemical, whereas naphthalene is a volatile compound. Because naphthalene is made up of nonpolar molecules held together only by van der Waals intermolecular forces, it rapidly sublimes, and benzoic acid remains in the mixture.
Therefore, the correct answer is option A sublimation.

Note: Magnesium hydride(\[Mg{H_2}\])is a white crystalline solid. It reacts violently with water and may ignite upon contact with air and is used to make other chemicals. If a cation has high polarising power, it pulls the large electron clouds from the anion forming a bond that is at least partially covalent. as far as \[Mg{H_2}\] is concerned Mg is a small relatively high charge ion and the H- ion is relatively large.