Question

Which of the following is used to separate oil from water?

• A. evaporation
• B. filtration
• C. separating funnel
• D. distillation

Answer 1

The correct option is C

separating funnel

The explanation for the correct option -

• Oil and water are a mixture of two immiscible liquids.
• Those liquids which do not mix with each other and form separate layers (when put in a container), are called immiscible liquids.
• A separating funnel is a specific sort of funnel that contains a stop-cock (or tap) in its stem that allows or stops the flow of liquid from it. The difference in densities between two immiscible liquids determines the separation by a separating funnel.
• Oil being lighter than water, forms the upper layer. now when the stopper of the funnel is opened slowly, the water (heavier liquid) comes out first and can be collected in a separate beaker.

The explanation for the incorrect options -

• Option A is incorrect because evaporation is a process of conversion of liquid into its vapors, even before reaching its boiling point. It is used to separate a solid from a liquid solution.
• Option B is incorrect because the process of removing insoluble solids from a liquid by using a filter paper is known as filtration. It is used to separate suspended solid particles from their solutions.
• Option D is incorrect because distillation is the process of separation of a liquid from its solution with a solid constituent by heating the liquid to its vapor form and then cooling the vapor to get back the pure liquid.

Hence, Option C is the correct answer.