Which of the following statement is correct for `CO` ?

Options

A. A double bond between `C` and `O` atoms
B. `1sigma,1pi` and 1 coordinate bond between `C` and `O` atoms
C. One lone pair of electrons on each atom
D. `1sigma,2pi` bonds between `C` and `O` atoms

Explanation

To determine the correct statement about carbon monoxide (CO), we will analyze the bonding and electron configuration of the molecule step by step.

### Step 1: Understand the Electron Configuration
- Carbon (C) has the electron configuration: 1s² 2s² 2p².
- Oxygen (O) has the electron configuration: 1s² 2s² 2p⁴.

### Step 2: Count the Valence Electrons
- Carbon has 4 valence electrons (2 from 2s and 2 from 2p).
- Oxygen has 6 valence electrons (2 from 2s and 4 from 2p).
- Total valence electrons in CO = 4 (from C) + 6 (from O) = 10 electrons.

### Step 3: Determine the Bonding
- To form a stable molecule, carbon and oxygen will share electrons.
- Carbon needs 4 electrons to complete its octet, while oxygen needs 2 electrons.

### Step 4: Forming Bonds
- Initially, carbon and oxygen can form a single bond by sharing one pair of electrons (1 sigma bond).
- After this, oxygen has 4 electrons remaining, and carbon has 3 electrons remaining.
- Oxygen can donate one of its lone pairs to carbon to form a coordinate (dative) bond, resulting in a double bond scenario.

### Step 5: Identify the Types of Bonds
- In CO, we have:
- 1 sigma bond (from the initial sharing of one pair of electrons).
- 1 pi bond (from the overlap of the remaining p orbitals).
- 1 coordinate bond (from the donation of a lone pair from oxygen to carbon).

### Step 6: Analyze the Statements
1. **Statement 1**: "A double bond between C and O atoms, one sigma, one pi, and one coordinate bond, one lone pair of electrons, and one sigma two pi bond."
- This statement is incorrect because it incorrectly describes the types of bonds.

2. **Statement 2**: "One sigma bond, one pi bond, and one coordinate bond."
- This statement is correct as it accurately describes the bonding in CO.

3. **Statement 3**: "One lone pair."
- This statement is incorrect because oxygen has one lone pair remaining after forming the coordinate bond.

4. **Statement 4**: "One sigma and two pi bonds."
- This statement is incorrect because CO does not have two pi bonds; it has one pi bond.

### Conclusion
The correct statement about CO is **Statement 2**: "One sigma bond, one pi bond, and one coordinate bond."

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