what is crystallisation? where it is used? why is this better than simple evaporation?
Answers
Crystallisation is a process that separates a pure solid in the form of its crystals from a solution. Crystallisation is better than evaporation because during Evaporation. Some impurities may remain dissolved in the solution even after filtration which on evaporation contaminates the solid.
Answer:
Crystallization is defined as a process by which a chemical is converted from a liquid solution into a solid crystalline state.
It helps to separate a pure solid from a solution in its crystal form. This is the in use to purify solid. For an example the salt we get from seawater can have many impurities in it. Hence, the process of crystallization is in use to remove these impurities.
Crystallisation is better than evaporation because during Evaporation some solids decompose or some, like sugar, may get charred on heating to dryness. Some impurities may remain dissolved in the solution even after filtration which on evaporation contaminates the solid. Impure solids are obtained by evaporation and are further purified by crystallisation. e.g. salt obtained from the sea is further purified by this method. In some cases e.g. sugar crystal cannot be obtained by simple evaporation technique because sugar gets charred on heating to dryness. In such cases, the crystallisation technique is applied.
hope it helps