Three test tubes marked A, B and C are taken. In test tube A copper sulphate solution and iron are added. In test tube B, copper sulphate solution and zinc are added. In test tube C, iron sulphate solution and copper are added. In which test tube will the experimenter observe change and why?

Explanation

To determine in which test tube the experimenter will observe a change, we need to analyze the reactions taking place in each test tube based on the reactivity series of metals.

### Step-by-Step Solution:

1. **Identify the Solutions and Metals in Each Test Tube**:
- Test Tube A: Copper sulfate (CuSO4) + Iron (Fe)
- Test Tube B: Copper sulfate (CuSO4) + Zinc (Zn)
- Test Tube C: Iron sulfate (FeSO4) + Copper (Cu)
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