(23) ) Write the steps involved in the process of obtaining pure copper sulphate from an
(ii) Give any one application of this method.
(111) Why is this technique better than simple evaporation to purify solids?
Answers
Answer:
The crystallisation method is used to purify solids
Explanation:
STEPS:
1.Take somepure sample of copper sulphate solution in a china dish.
2. Dissolve it in minimum amount of water.
3.Filter the impurities out using filter paper.
4.Evaporate water from copper sulphate solution so as to get a saturated solution.
5.Cover the solution with a filter paper and leave it undisturbed to cool slowly.
6.The pure crystals of copper sulphate is obtained which can be dried later.
The two applications of crystallisation are-
a) Removal of salt from sea water. As salt in sea water is very high, it needs to be removed in order to use it for practical applications.
b) Separation of pure crystals from the impure ones. This helps in purifying the salt for regular household use.
Why is this technique better than simple evaporation to purify solids?
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.