Copper sulphate was placed in an aluminium can. After a few days holes appeared in the can. Explain this observation.

Explanation

### Step-by-Step Text Solution:

1. **Understanding the Materials**: The question states that copper sulfate (CuSO4) is placed in an aluminum can. Copper sulfate is a blue crystalline solid that is soluble in water, and it contains copper ions (Cu²⁺) and sulfate ions (SO4²⁻).

2. **Reactivity Series**: In order to understand why holes appeared in the aluminum can, we need to refer to the reactivity series of metals. The reactivity series ranks metals based on their ability to displace other metals from compounds. In this series, aluminum is more reactive than copper.

3. **Displacement Reaction**: Since aluminum is more reactive than copper, it can displace copper from copper sulfate. This means that when aluminum comes into contact with copper sulfate, a chemical reaction occurs where aluminum replaces copper in the compound.

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