When 1 mole of anhydrous `CuSO_(4)` is dissolved in excess of water, -66.4 kJ heat is evolved. When one mole of `CuSO_(4).5H_(2)O` is dissolved in water, the heat change is +11.7 kJ. Calculate enthalpy of hydration of `CuSO_(4)` (anhydrous).

Explanation

To calculate the enthalpy of hydration of anhydrous CuSO₄, we can use the information provided about the dissolution of both anhydrous CuSO₄ and its hydrate, CuSO₄·5H₂O. Here’s a step-by-step solution:

### Step 1: Write the dissolution equations
1. For anhydrous CuSO₄:
\[ \text{CuSO}_4 (s) + \text{H}_2O (l) \rightarrow \text{CuSO}_4 (aq) \quad \Delta H_1 = -66.4 \text{ kJ} \]
This indicates that when 1 mole of anhydrous CuSO₄ is dissolved in water, 66.4 kJ of heat is released (exothermic process).
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