Question

Name the principle by which the mixture of salt and sand is separated into its component.

Answer 1

Filtration is the principle by which the mixture of salt and sand is separated into its component.

Filtration to separate a mixture of salt solution and sand:
Salt is soluble in water whereas sand is insoluble in water. This difference in the solubility of salt and sand in water is used to separate them. This is done as follows.

• The mixture of salt and sand is taken into a beaker and water is added to it. The mixture is stirred to dissolve the salt. The sand remains undissolved.
• The salt solution containing sand is filtered by pouring over a filter paper kept in a funnel. Sand remains as a residue on the filter paper and salt solution is obtained as a filtrate in the beaker kept below the funnel.
• The salt solution is evaporated carefully to get the crystals of salt.

In this way, a mixture of salt and sand has been separated by using water as the solvent.