Question

Separation of crystals of alum from an impure sample is carried out through:

• A. Centrifugation
• B. Distillation
• C. Crystallization
• D. None of the above.

Answer 1

The correct option is C

Crystallization

Explanation for correct option:

Option C

Crystallization:

• Crystallization is a complex process through which solid forms, where the atoms or molecules are strongly packed into a structure known as a crystal.
• Crystallization is a chemical process in which the solid-liquid separation technique occurs.
• This process causes the mass transfer of a solute from the liquid solution to a pure solid crystalline phase.
• For example, the separation of crystals of potash alum from an impure sample is carried out through crystallization

Explanation for incorrect option:

Option A

Centrifugation:

• It is a method used for the separation of fine suspended particles of a substance in a liquid.
• In this method, the liquid containing the fine suspended particles is rotated at a very high speed in a closed container.
• The heavier particles move towards the bottom of the container and the lighter particles remain above the heavier ones on the top.
• This method is used in dairies to separate cream from milk.

Option B

Distillation:

• It is the process of the separation of a liquid from its solution with solid constituents by heating the liquid to its vapor form and then cooling the vapor to get back to the pure liquid.
• This method is used to recover both the dissolved solids and the liquid from their mixture.

Hence, option (C) is the correct answer. The separation of crystals of alum from an impure sample is carried out through crystallization.