Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) :` Cu^(2+)` in water is more stable then `Cu^(2+)` .
Reason (R) : Enthalpy of hydration for` Cu^(2+)` is much less than of `Cu^(+)` .
In the light of the above statements, choose the correct answer from the options given below :

Options

A. Both (A) and (R) are correct and (R) is the correct explanation of (A
B. (A) is correct but (R) is not correct
C. Both (A) and (R) are correct but (R) is not the correct explanation of (A)
D. (A) is not correct but (R) is correct

Answer

To solve the question, we need to analyze both the Assertion (A) and the Reason (R) provided.

### Step 1: Analyze the Assertion (A)
Assertion (A) states that `Cu^(2+)` in water is more stable than `Cu^(+)`.

- **Stability in Water**: The stability of a cation in water can be assessed based on its hydration enthalpy. A higher hydration enthalpy indicates that the cation is more stable in an aqueous solution because it interacts more favorably with water molecules.

### Step 2: Analyze the Reason (R)
Reason (R) states that the enthalpy of hydration for `Cu^(2+)` is much less than that of `Cu^(+)`.

- **Enthalpy of Hydration**: The enthalpy of hydration is the energy released when ions are surrounded by water molecules. Generally, smaller ions with higher charge density have higher hydration enthalpy because they can attract water molecules more effectively.

### Step 3: Compare the Sizes and Charges
- **Size and Charge**: `Cu^(2+)` has a higher charge (+2) compared to `Cu^(+)` (+1). The increased positive charge in `Cu^(2+)` leads to a greater attraction to water molecules, resulting in a smaller ionic radius compared to `Cu^(+)`.

### Step 4: Evaluate the Hydration Enthalpy
- Since `Cu^(2+)` is smaller and has a higher charge, it will have a more negative (higher) enthalpy of hydration compared to `Cu^(+)`. Thus, the statement in Reason (R) is incorrect.

### Conclusion
- **Assertion (A)** is correct: `Cu^(2+)` is indeed more stable in water than `Cu^(+)`.
- **Reason (R)** is incorrect: The enthalpy of hydration for `Cu^(2+)` is greater than that of `Cu^(+)`, not less.

### Final Answer
The correct conclusion is that Assertion (A) is true, but Reason (R) is false.

---