According to the Valence bond theory, which statement is incorrect regarding bonding between two carbon atoms ?

Options

A. A sigma `(sigma)` bond is weaker than a `pi-` bond
B. A sigam bond is stronger than a `pi-` bond
C. A double bond is stronger than a single bond
D. A double bond is shorter than a single bond

Answer

To determine the incorrect statement regarding bonding between two carbon atoms according to Valence Bond Theory, we will analyze each option provided.

### Step-by-Step Solution:

1. **Understanding Sigma and Pi Bonds**:
- A **sigma bond** is formed by the end-to-end (or head-on) overlap of atomic orbitals. This overlap occurs along the internuclear axis and is characterized by a larger extent of overlap, making sigma bonds generally stronger.
- A **pi bond** is formed by the side-to-side overlap of p orbitals. This overlap is lateral and has a smaller extent compared to sigma bonds, making pi bonds generally weaker.

2. **Evaluating the Statements**:
- **Statement 1**: "A sigma bond is weaker than a pi bond."
- This statement is incorrect because sigma bonds are stronger than pi bonds due to the greater extent of overlap.

- **Statement 2**: "A sigma bond is stronger than a pi bond."
- This statement is correct. Sigma bonds are indeed stronger than pi bonds.

- **Statement 3**: "A double bond is stronger than a single bond."
- This statement is also correct. A double bond (which consists of one sigma and one pi bond) is stronger than a single bond (which consists of only one sigma bond).

- **Statement 4**: "A double bond is shorter than a single bond."
- This statement is correct as well. With increased bond multiplicity (from single to double), the bond length decreases.

3. **Conclusion**:
- The incorrect statement regarding bonding between two carbon atoms according to Valence Bond Theory is **Statement 1**: "A sigma bond is weaker than a pi bond."

### Final Answer:
The incorrect statement is: **"A sigma bond is weaker than a pi bond."**

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