Statement-1: Cyanides are more polar than isocyanides.
and
Statement-2: Isocynides show addition of oxygen or sulphur with HgO or HgS respectively.

Options

A. Statement-1 is true, Statement-2 is true, statement-2 is a correct explanation for statement-9
B. Statement-1 is true, statement-2 is true, statement-2 is not a correct explanation for statement-9
C. Statement-1 is true, statement-2 is False
D. Statement-1 is False, Statement-2 is True.

Answer

To solve the problem, we need to analyze both statements provided and determine their validity.

### Step 1: Analyze Statement 1
**Statement 1:** Cyanides are more polar than isocyanides.

- **Understanding Polarity:** Polarity in a molecule is determined by the dipole moment, which arises from differences in electronegativity between atoms. A bond is polar if there is a significant difference in electronegativity between the two atoms involved.

- **Cyanides:** In cyanides (R-C≡N), the carbon atom is bonded to a nitrogen atom. The electronegativity of carbon (2.5) is less than that of nitrogen (3.0). This creates a dipole moment directed from carbon to nitrogen, making the C-N bond polar.

- **Isocyanides:** In isocyanides (R-N≡C), the nitrogen atom is bonded to a carbon atom. Here, nitrogen is again more electronegative than carbon, leading to a dipole moment directed from nitrogen to carbon. However, the triple bond between nitrogen and carbon in isocyanides has a higher bond order, which can influence the overall dipole moment.

- **Conclusion for Statement 1:** The dipole moment of cyanides is greater than that of isocyanides due to the orientation of the dipoles. Therefore, cyanides are indeed more polar than isocyanides. **Statement 1 is true.**

### Step 2: Analyze Statement 2
**Statement 2:** Isocyanides show addition of oxygen or sulphur with HgO or HgS respectively.

- **Reactions of Isocyanides:** Isocyanides can react with mercuric oxide (HgO) to form an alkyl isocyanate (R-N=C=O), indicating the addition of oxygen. Similarly, they can react with mercuric sulfide (HgS) to form an alkyl thiocyanate (R-N=C=S), indicating the addition of sulfur.

- **Conclusion for Statement 2:** Both reactions confirm that isocyanides do indeed show addition of oxygen and sulfur when reacted with HgO and HgS, respectively. **Statement 2 is true.**

### Step 3: Determine the Relationship Between the Statements
- **Correct Explanation:** While both statements are true, Statement 2 does not explain why cyanides are more polar than isocyanides. The polarity is based on dipole moments, not on the reactions with HgO or HgS.

### Final Conclusion
- **Answer Options:**
- Option 1: Statement 1 is true, Statement 2 is true, and Statement 2 is a correct explanation for Statement 1. (Incorrect)
- Option 2: Statement 1 is true, Statement 2 is true, and Statement 2 is not a correct explanation for Statement 1. (Correct)
- Option 3: Statement 1 is true, Statement 2 is false. (Incorrect)
- Option 4: Statement 1 is false, Statement 2 is true. (Incorrect)

Thus, the correct answer is **Option 2**.