Question

You are given a mixture of sand, salt, water, and oil. Select the method of separation for each of component, and the correct order of its usage from the given options.

• A. Filtration, Separating funnel, Centrifugation
• B. Crystallisation, Centrifugation, Separating funnel
• C. Filtration, Separating funnel, Crystallisation
• D. Separating funnel, Crystallisation, Centrifugation

Answer 1

The correct option is C Filtration, Separating funnel, Crystallisation

Salt dissolves in water to form a homogeneous mixture. Oil is immiscible in water and keeps floating on the water surface. Sand in water is a suspension that settles down when kept undisturbed for a while.

The best way to separate the mixture will be to first remove the particles that are undissolved. So sand will be removed first from the mixture by filtration. After removing sand, oil can be removed from the mixture using a separating funnel since oil and water are immiscible.

At last, salt can be removed by a crystallisation process where crystals of salt will be removed from its solution.