Question

The process of separation of cream from milk is called:
[A] Emulsification.
[B] Demulsification.
[C] Electro-osmosis.
[D] Peptization.

Answer 1

Hint: Here, the process uses the centrifugation process to separate cream from milk. Emulsification is the process of mixing two immiscible liquids to form emulsion and demulsification is the process of breaking the emulsion solution.

Complete step by step solution: Before answering this question, let us understand what the terms mentioned in the options mean and then try to find the correct answer.
Firstly, we have an emulsification. It is a process in which two immiscible liquids in semi-stable states are produced. Generally, one is the oil phase and the other is an aqueous phase. The oil phase is present in the form of small droplets in the aqueous phase.
Next, we have demulsification. It is the process of breaking oil in an emulsion solution. It separated the oil part from the aqueous part in a mixture. There are special chemicals and processes that are used to carry out this process.
Then we have electro-osmosis which is basically osmosis under an applied electrical field. Here, the flow of liquid across the semipermeable membrane is induced by an electrical potential.
Lastly, we have peptization which is the process of formation of stable dispersion colloids in a dispersion medium.
In the question, the process of separation of cream and milk is asked. As we can understand from the above discussion that separation of oil and the aqueous phase is termed as demulsification. Here, the cream is the oil part separated from milk i.e. the aqueous part. Therefore, the process of separation of cream from milk is demulsification.

Therefore, the correct answer is an option [B] Demulsification.

Note: We know that milk is a suspension mixture of cream in a watery liquid. We use the process of centrifugation to separate cream from milk. We put the milk in a close container in a big centrifuge machine and the container is spun at a very high speed. The centrifugal forces act on milk and thus separate the mixture into a cream which is lighter thus floats on top and skimmed milk which is at the bottom. Then cream can be separated from the milk.