Question

Crystallisation is better than simple evaporation because:

• A. soilds can decompose
• B. may get charred when heated to dryness
• C. the contaminant can still be present
• D. all of these

Answer 1

The correct option is D

all of these

Crystallisation is better than simple evaporation because:
1. The process of evaporation gives a residue which may contain some impurities. Whereas, through crystallisation method, we obtain a solid without any impurity.
2. Evaporation is a slow process, so usually, heat is supplied to speed it up. But often, heat has an adverse effect on the mixture that is to be separated. This happens because a few soilds can decompose and may get charred when heated to dryness.