The salts of Cu in +1 oxidation state are unstable because

Options

A. `Cu^(+)" had " 3d^(10)` configuration
B. `Cu^(+)` disproportionates easily to Cu (0) and `Cu^(2+)`
C. `Cu^(+)` disproptionates easily to `Cu^(2+)" and " Cu^(3+)`
D. `Cu^(+)` is easily reduced to `Cu^(2+)`

Explanation

To solve the question regarding the instability of copper salts in the +1 oxidation state, we can break down the explanation into clear steps:

### Step-by-Step Solution:

1. **Understanding Oxidation States of Copper**:
- Copper can exist in multiple oxidation states, primarily +1 (Cu⁺) and +2 (Cu²⁺). The +1 oxidation state is less stable compared to the +2 state.

2. **Disproportionation Reaction**:
- The salts of copper in the +1 oxidation state tend to undergo a disproportionation reaction. This means that the Cu⁺ ions can simultaneously oxidize and reduce themselves to form Cu²⁺ and Cu⁰ (metallic copper).
- The reaction can be represented as:
\[ 2 \text{Cu}^+ \rightarrow \text{Cu}^{2+} + \text{Cu}^0 \]

3. **Hydration Enthalpy**:
- The stability of ions in solution is influenced by their hydration enthalpy, which is the energy released when water molecules surround an ion.
- Hydration enthalpy is directly proportional to the charge of the cation. Therefore, Cu²⁺, having a higher charge than Cu⁺, will have a greater hydration enthalpy.

4. **Comparison of Hydration**:
- In an aqueous solution, Cu²⁺ ions attract more water molecules due to their higher charge, leading to greater stabilization compared to Cu⁺ ions.
- This means that Cu²⁺ ions are more stable in solution because they are better hydrated.

5. **Conclusion**:
- Due to the tendency of Cu⁺ to disproportionate into Cu²⁺ and Cu⁰, along with the greater stability provided by the higher hydration enthalpy of Cu²⁺, the salts of copper in the +1 oxidation state are unstable.

### Final Answer:
The salts of Cu in the +1 oxidation state are unstable because they readily disproportionate into Cu²⁺ and Cu⁰ due to the higher stability of Cu²⁺ resulting from its greater hydration enthalpy.

---