Question

Name the technique to separate:
(A) butter from curd
(B) salt from sea water
(C) camphor from salt

Answer 1

Hint: Number of substances that exist in nature are not present in their ultimate purest form. These substances are contaminated with different types of foreign particles. Therefore, a specific separation technique is required to obtain the pure form of the compound.

Complete Step By Step Answer:
Butter from curd is separated by the process of centrifugation. In the centrifugation technique particles are separated based upon their size, density of particles, viscosity of medium used, shape of particles to be separated as well as speed of centrifugal machine. Butter and curd differ in their viscosity, density and size of particles therefore they are easily separated by centrifugation method.

(A) Butter from curd is separated by the process of centrifugation, Salt from sea water is separated by evaporation or crystallization process and Camphor from salt separated by the process of sublimation.

(B) Salt from sea water is easily separated by the process of evaporation which is based on the difference in volatility of components in the mixture. As we know that water is volatile in nature when appropriate temperature is applied. So, water molecules start evaporating leaving nonvolatile salt behind and thus cause the separation of salt. Another approach to separate Salt from sea water is done by process of crystallization.

(C) Camphor from salt is separated by the process of sublimation in which a solid component is directly converted into its gaseous state avoiding conversion to liquid state. Camphor is a sublimable compound which has a tendency to directly convert into gas without forming liquid.

Note:
The basic force which aids the process of centrifugation is centrifugal force. On applying external gravitational force to the mixture, the rate of separation is enhanced. Process of crystallization is basically based upon the difference in solubility of components of mixture. Process of sublimation is also used for benzoic acid, anthracene or naphthalene.