Which of the following has shortest carbon-carbon bond length?

Options

A. `C_(2)H_(2)`
B. `C_(2)H_(4)`
C. `C_(2)H_(6)`
D. `C_(6)H_(6)`

Explanation

To determine which of the given compounds has the shortest carbon-carbon bond length, we need to analyze the types of bonds present in each compound.

### Step-by-Step Solution:

1. **Identify the Compounds**:
- The compounds mentioned are C2H2, C2H4, C2H6, and C6H6.
- C2H2 is Ethyne (an alkyne).
- C2H4 is Ethene (an alkene).
- C2H6 is Ethane (an alkane).
- C6H6 is Benzene (a cyclic compound).

2. **Understand the Types of Bonds**:
- **Single Bonds**: Present in alkanes (e.g., C2H6).
- **Double Bonds**: Present in alkenes (e.g., C2H4).
- **Triple Bonds**: Present in alkynes (e.g., C2H2).
- **Aromatic Bonds**: Present in cyclic compounds like Benzene (C6H6).

3. **Bond Length Order**:
- The bond lengths decrease in the following order:
- Single bond (longest) > Double bond > Triple bond (shortest).
- Therefore, the bond length order is:
- C-C (single) > C=C (double) > C≡C (triple).

4. **Determine the Shortest Bond**:
- Since C2H2 (ethyne) contains a triple bond, it will have the shortest carbon-carbon bond length compared to the other compounds which contain single or double bonds.

5. **Conclusion**:
- The compound with the shortest carbon-carbon bond length is C2H2 (ethyne).

### Final Answer:
C2H2 (ethyne) has the shortest carbon-carbon bond length.