The bond order between C and C in acetylene molecule is

Options

A. 1
B. 2
C. 3
D. 4

Answer

To determine the bond order between the carbon atoms in the acetylene molecule (C₂H₂), we can follow these steps:

### Step 1: Understand the Structure of Acetylene
Acetylene (C₂H₂) consists of two carbon atoms connected by a triple bond. Each carbon atom is also bonded to one hydrogen atom.

### Step 2: Identify the Type of Bonding
In acetylene, the carbon atoms are bonded through:
- One sigma (σ) bond
- Two pi (π) bonds

### Step 3: Calculate the Bond Order
The bond order can be calculated using the formula:
\[ \text{Bond Order} = \frac{\text{Number of bonding electrons} - \text{Number of antibonding electrons}}{2} \]
For acetylene:
- There are 6 bonding electrons (1 σ bond contributes 2 electrons and 2 π bonds contribute 4 electrons).
- There are no antibonding electrons in the case of a simple acetylene molecule.

Thus, the bond order can be calculated as:
\[ \text{Bond Order} = \frac{6 - 0}{2} = 3 \]

### Step 4: Conclusion
The bond order between the carbon atoms in the acetylene molecule is 3, indicating a triple bond.

---