The heat of solution of anhydrous `CuSO_(4)` is `-66.5` kJ and that of `CuSO_(4).5H_(2)O` is 11.7 kJ . Calculate is the heat of hydration of `CuSO_(4)`.

Explanation

To calculate the heat of hydration of anhydrous CuSO₄, we can use the given heats of solution for both anhydrous CuSO₄ and hydrated CuSO₄·5H₂O.

### Step-by-Step Solution:

1. **Identify the Given Values:**
- Heat of solution of anhydrous CuSO₄ (ΔH₁) = -66.5 kJ
- Heat of solution of CuSO₄·5H₂O (ΔH₂) = +11.7 kJ

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