Give an example of chemical changes of a reaction involving blue solution.

Explanation

**Step-by-Step Text Solution:**

1. **Identify the Blue Solution**: The blue solution mentioned in the question is a solution of copper sulfate (CuSO₄).

2. **Introduce the Reactant**: To demonstrate a chemical change involving this blue solution, we will use iron (Fe) needles as the reactant.

3. **Describe the Reaction**: When iron needles are dipped into the copper sulfate solution, a chemical reaction occurs. Iron is more reactive than copper.

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