CHEMISTRY [3 Mark Question Answer]

(a) Evaporation Method :-
1. The evaporation method is used to separate salt from seawater.
2. As water molecules absorb heat from the Sun, they transform into water vapors that disperse into the atmosphere, leaving behind salt since salt has a much higher boiling point.
(b) Sedimentation and decantation methods are used for the separation of insoluble substances which are heavier than liquid. In the sedimentation process, heavier components of the mixture settle on the bottom, due to gravity. Decantation follows sedimentation.

Mixture - Common salt and Marble powder.
• Principle - Different constituents have different solubility in various solvents.
• Common salt is water-soluble while marble powder is not.
• Method of separation :-
1. Dissolve the mixture in a good amount of water such that the soluble component of the mixture, common salt completely dissolves.
2. Now filter the solution.
3. The insoluble component which is marble powder will be left on the filter paper.
4. Let the powder dry. Marble powder will be recovered.
5. Now, slowly heat the filtrate, such that all the water gets evaporated.
6. Salt particles will be left behind as a residue.