Question

How will you separate sand and water from their mixture ?

Answer 1

Hint: Heavier components in a liquid mixture can be separated by sedimentation followed by decantation or by filtration.

Complete answer:
First method - Sedimentation followed by decantation :
In a sand water mixture, sand is a heavy particle. Hence sand water mixture can be separated by sedimentation method. First, leave the sand water mixture undisturbed for some time. Then the heavier sand particles will settle down on the bottom of the container. The upper portion will be water and the lower portion will be sand. This process is called sedimentation. Then the water in the upper portion can be transferred into another container. This should be done very carefully without disturbing the lower part of the mixture. This process is called decantation. Then the sand particles will remain on the beaker and water on another beaker. Hence the sand water mixture is separated.
Second method - Filtration :
In this method, the sand-water mixture is passed through a filter paper with fine pores. Sand particles are large in size. Hence it cannot pass through the filter paper. The very small pores on filter paper blocks the sand particles. But water can easily pass through the filter paper. Hence sand particles are retained on filter paper and sand water mixture is separated.

Note:
These methods are used because sand is insoluble in water and is heavier than water. If the particle is soluble in water, we cannot use these methods for their separation.