Impure copper sulphate powder can be purified by the process of :

Options

A. galvanisation
B. crystallisation
C. evaporation
D. sublimation

Answer

**Step-by-Step Solution:**

1. **Identify the Process**: The question asks how to purify impure copper sulfate powder. The appropriate method for this is crystallization.

2. **Dissolve the Impure Sample**: Begin by taking the impure copper sulfate powder and dissolving it in a suitable solvent. Water is commonly used as the solvent for copper sulfate.

3. **Heat the Solution**: After dissolving the impure copper sulfate, heat the solution using a water bath. This helps to ensure that all of the copper sulfate dissolves completely.

4. **Allow to Stand**: Once the solution is heated and well mixed, allow it to stand undisturbed for some time. During this period, the solution will cool down.

5. **Formation of Crystals**: As the solution cools, pure copper sulfate crystals will start to form. This occurs because the solubility of copper sulfate decreases as the temperature drops, leading to the crystallization of the pure substance.

6. **Separation of Crystals**: After sufficient time has passed, the pure crystals can be separated from the remaining solution. This can be done by filtration or decantation.

7. **Drying the Crystals**: Finally, the separated crystals should be dried to remove any residual solvent.

**Final Answer**: Impure copper sulfate powder can be purified by the process of crystallization.

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