A:`CN^(-)` is an acid ligand. R: `CN^(-)` accepts electron pair also.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1)
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2).
C. ) If Assertion is true statement but Reason is false, then mark (3).
D. If both Assertion and Reason are false statements, then mark (4)

Answer

To analyze the given statements about the ligand CN^(-), we will break down the assertion and reason step by step.

### Step 1: Understand the Assertion
The assertion states that CN^(-) is an acid ligand.

- **Analysis**:
- A ligand is a species that can donate a pair of electrons to a metal center in a coordination compound.
- Acid ligands typically refer to species that can accept electron pairs, which is contrary to the behavior of CN^(-).

### Step 2: Evaluate the Assertion
- Since CN^(-) is known to be a strong field ligand and acts as a Lewis base (donating electron pairs), it cannot be classified as an acid ligand.

**Conclusion for Assertion**: The assertion is **false**.

### Step 3: Understand the Reason
The reason states that CN^(-) accepts an electron pair.

- **Analysis**:
- Accepting an electron pair is characteristic of Lewis acids, while donating an electron pair is characteristic of Lewis bases.
- CN^(-) is a Lewis base because it has a lone pair of electrons that it can donate.

### Step 4: Evaluate the Reason
- Since CN^(-) does not accept electron pairs but rather donates them, the reason is also incorrect.

**Conclusion for Reason**: The reason is **false**.

### Final Conclusion
Both the assertion and the reason are false. Therefore, the correct answer is that both statements are incorrect.