Mention with reason the colour changes observed when :
a piece of zinc is dropped in copper sulphate solution.

Explanation

### Step-by-Step Solution:

1. **Understanding the Reaction**: When a piece of zinc is dropped into a copper sulfate solution, a chemical reaction occurs. This is known as a displacement reaction, where a more reactive metal displaces a less reactive metal from its compound.

2. **Identifying the Reactants**: The reactants in this case are:
- Zinc (Zn) - a more reactive metal.
- Copper sulfate (CuSO₄) - a blue solution.

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