The electronegativities of acetylene, ethylene and ethane are in the order :

Options

A. ethylene > acetylene > ethane
B. acetylene > ethylene > ethane
C. ethane > acetylene > ethylene
D. acetylene > ethane > ethylene

Answer

To determine the order of electronegativities of acetylene, ethylene, and ethane, we need to analyze the hybridization of the carbon atoms in each of these compounds.

### Step 1: Identify the Hybridization
- **Acetylene (C2H2)**: The carbon atoms in acetylene are sp hybridized.
- **Ethylene (C2H4)**: The carbon atoms in ethylene are sp² hybridized.
- **Ethane (C2H6)**: The carbon atoms in ethane are sp³ hybridized.

### Step 2: Understand Electronegativity and Hybridization
The electronegativity of carbon atoms varies with their hybridization:
- sp hybridized carbon atoms have the highest electronegativity.
- sp² hybridized carbon atoms have a lower electronegativity than sp.
- sp³ hybridized carbon atoms have the lowest electronegativity.

### Step 3: Compare the Electronegativity
Based on the hybridization:
- **Acetylene (sp)** > **Ethylene (sp²)** > **Ethane (sp³)**

### Conclusion
Thus, the order of electronegativities is:
**Acetylene > Ethylene > Ethane**

### Final Answer
The correct order of electronegativities is:
**Acetylene > Ethylene > Ethane**