Assertion : Cuprous ion ` (Cu^(+))` is colouless whereas cupric ion `(Cu^(++))` is blue in the aqueous solution.
Reason : Cuprous ion `(Cu^(+))` has unpaired electrons while cupric ion `(Cu^(++))` does not .

Options

A. If both the assertion and reason are true and reason is correct explanation of the assertion .
B. If both the assertion and reason are true but reason is not a correct explanation of the assertion .
C. If the assertion is true but the reason is false.
D. If both assertion and reason are false.

Explanation

To solve the question, we need to analyze both the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that the cuprous ion (Cu⁺) is colorless while the cupric ion (Cu²⁺) is blue in aqueous solution.
- This is a true statement. Cu⁺ is indeed colorless, and Cu²⁺ typically appears blue in solution due to its electronic structure.

**Hint**: Recall that the color of transition metal ions in solution is often related to their electronic configurations and the presence of unpaired electrons.

2. **Understanding the Reason**:
- The reason given is that the cuprous ion (Cu⁺) has unpaired electrons while the cupric ion (Cu²⁺) does not.
- This statement is false. In fact, the cuprous ion (Cu⁺) has a full d-subshell configuration (3d¹⁰) and does not have unpaired electrons, making it colorless. Conversely, the cupric ion (Cu²⁺) has an electronic configuration of 3d⁹, which means it has one unpaired electron, contributing to its blue color.

**Hint**: Remember that the presence of unpaired electrons in transition metals is what often leads to color in their compounds.

3. **Conclusion**:
- Since the assertion is true and the reason is false, the correct answer is that the assertion is true but the reason is false.

**Final Answer**: The assertion is true, and the reason is false.

### Summary:
- **Assertion**: True (Cu⁺ is colorless; Cu²⁺ is blue).
- **Reason**: False (Cu⁺ does not have unpaired electrons; Cu²⁺ does).