Question

What is crystallization? Where is it used? Why is this better than simple evaporation technique?

Answer 1

Answer:

Crystallization is the method used to obtain crystals of pure substance from impure sample.

Uses: It is used in purification of salt from sea water

It is used to separate crystals of alum from impure alum

*This method is better than evaporation because it removes even soluble impurities*

Answer 2

Explanation:

• Crystallization or crystallisation is the (natural or artificial) process by which a solid forms, where the atoms or molecules are highly organized into a structure known as a crystal. Some of the ways by which crystals form are precipitating from a solution, freezing, or more rarely deposition directly from a gas. Attributes of the resulting crystal depend largely on factors such as temperature, air pressure, and in the case of liquid crystals, time of fluid.
• It is used to separate salt particals which is mixed with sea water.
• Crystallization is used in the chemistry laboratory as a purification technique for solids. An impure solid is completely dissolved in a minimal amount of hot, boiling solvent, and the hot solution is allowed to slowly cool.
• Crystallisation technique for purification is better than evaporation because: ... Crystallisation does not require very high temperature conditions, there is no need to boil the solvent. In evaporation, we allow the solution to heat to make the solvent evaporate but this may degrade the solute into some another compound.

May this help you.