Question

You are provided with a mixture of salt, sand, oil, and water. Write the steps involved for the separation of salt, sand, and oil from the mixture.

Answer 1

In the mixture of salt, sand, oil, and water, salt is soluble in water, whereas sand is insoluble in water. Oil, also, is immiscible in water.

Hence, the mixture can be separated by using these steps-​

i) Decantation: Oil floats on water, so it can be decanted easily.​

ii) Filtration: In the remaining mixture of salt, sand, and water, sand can be separated from salt solution using filtration. When passed through a filter paper, sand stays on the filter paper as a residue, whereas the salt solution passes through the filter paper as filtrate.

iii) Evaporation and Condensation: We are now left with the mixture of salt and water. The salt solution can be heated. The water gets evaporated, leaving the salt behind in the beaker. The water vapoours can be converted to liquid water droplets through condensation.