Question

In oxygen and carbon molecule the bonding is

• A. \(O_2: 1\sigma, 1\pi; \text{C}_2: 0\sigma, 2\pi\)
• B. \(O_2: 1\sigma, 1\pi; \text{C}_2: 1\sigma, 1\pi\)
• C. \(O_2: 0\sigma, 2\pi; \text{C}_2: 2\sigma, 0\pi\)
• D. \(O_2: 2\sigma, 0\pi; \text{C}_2: 0\sigma, 2\pi\)

Answer 1

The Correct Option is A

Correct Answer: \(O_2: 1\sigma, 1\pi; \text{C}_2: 0\sigma, 2\pi\)

Explanation: 
To determine the bonding in diatomic molecules like \(O_2\) and \(C_2\), we use Molecular Orbital Theory (MOT).

• O₂ molecule:
- Total bond order: 2 (based on MO diagram)
- Bonding: 1 σ bond (from \(2s\) or \(2p_z\)) and 1 π bond (from \(2p_x\) & \(2p_y\))
⇒ So, bonding in \(O_2\): 1σ and 1π

• C₂ molecule:
- Total bond order: 2
- Due to the electron configuration, the two bonds in C₂ are both π bonds.
- There is no net σ bond from 2p orbitals.
⇒ So, bonding in \(C_2\): 0σ and 2π

Therefore, the correct bonding is:
\(O_2: 1σ, 1π; \text{C}_2: 0σ, 2π\)

Answer 2

The statement (A) is correct. In an oxygen molecule (O₂), there is a sigma (\(\sigma\)) bond and a pi (\(\pi\)) bond between the two oxygen atoms.
The sigma bond is formed by the overlap of two atomic orbitals along the internuclear axis, while the pi bond is formed by the sideways overlap of p orbitals. On the other hand, in a carbon molecule (C₂), there are no sigma bonds but two pi bonds between the two carbon atoms.
So, the correct answer is (A) O₂: 1σ, 1 π; C2: 0σ, 2π.