Choose the correct order of C-C bond length in the given compounds:

Options

A. Acetylene`lt`ethylene`lt`graphite`lt`benzene`lt`ethane
B. acetylene`lt`ethylene`lt`benzene`lt`graphite`lt`ethane
C. acetylene`lt`graphite`lt`ethylene`lt`benzene`lt`ethane
D. acetylene`lt`benzene`lt`graphite`lt`entylene`lt`ethane

Answer

To determine the correct order of C-C bond lengths in the given compounds, we need to analyze the types of bonds present in each compound. The compounds we are considering are acetylene, ethylene, graphite, benzene, and ethane.

### Step-by-Step Solution:

1. **Identify the Compounds and Their Bond Types**:
- **Acetylene (C2H2)**: Contains a triple bond (C≡C).
- **Ethylene (C2H4)**: Contains a double bond (C=C).
- **Graphite**: Consists of sp² hybridized carbon atoms bonded in sheets, primarily involving single bonds (C-C) with some delocalized π-bonds.
- **Benzene (C6H6)**: Contains sp² hybridized carbon atoms with delocalized π-bonds, giving it a resonance structure but primarily single bond character.
- **Ethane (C2H6)**: Contains a single bond (C-C).

2. **Understanding Bond Lengths**:
- Single bonds (C-C) are the longest.
- Double bonds (C=C) are shorter than single bonds.
- Triple bonds (C≡C) are the shortest.
- In graphite and benzene, while they have some double bond character due to resonance, they are primarily considered as single bonds.

3. **Rank the Compounds by Bond Length**:
- **Longest Bond Length**: Ethane (C-C single bond) > Graphite (C-C single bond with some delocalization) > Benzene (C-C with partial double bond character) > Ethylene (C=C double bond) > Acetylene (C≡C triple bond).
- Therefore, the order from longest to shortest bond length is:
- Ethane > Graphite > Benzene > Ethylene > Acetylene.

4. **Conclusion**:
- The correct order of C-C bond lengths in the given compounds is:
- **Ethane > Graphite > Benzene > Ethylene > Acetylene**.

### Final Answer:
The correct order of C-C bond lengths is: **Ethane > Graphite > Benzene > Ethylene > Acetylene**.