Question

A container contains a mixture of sand, salt and pebbles. How can each substance be separated from each other?

Answer 1

Hint:The salt is soluble in water whereas sand and pebbles are not. The salt and pebbles are heavier in weight and get settled in the beaker. The methods involved in the separation are filtration, evaporation.

Complete step by step answer:
The given mixture contains sand, salt and pebbles. Each compound from the mixture can be separated from each other by different techniques.
First dissolve the mixture in the water. The salt being soluble in water, dissolves in water and forms an aqueous solution. The sand and pebbles are not soluble in water so they will remain in the water.
The mixture solution is then passed through the sieve. The aqueous solution and the sand will pass through the sieve and the pebbles will be separated out.
Now the aqueous solution containing sand is filtered using a filter paper connected to a beaker. When the mixture is passed through the filter paper, the aqueous solution passes from the paper and gets collected in the beaker and the sand gets settled in the filter paper. This is how sand is removed from the salt solution.
The salt solution is then boiled at high temperature so the water gets evaporated and the salt crystals are obtained.
This is how a mixture of sand, salt and pebbles are separated from each other.

Note:
We can also think of decantation as sand and pebbles are heavier in weight and get settled down in the beaker and the aqueous solution can be decant in other beakers but after that it will be difficult to separate pebbles and sand from each other.