In which complex C-O bond length is maximum ?

Options

A. `CH_(3) CHO`
B. `CO_(2)`
C. `CO`
D. `CO_(3)^(2-)`

Answer

To determine which complex has the maximum C-O bond length among the given compounds, we can analyze the bond types and resonance structures of each compound. Here's a step-by-step solution:

### Step 1: Identify the Compounds
We have the following compounds to analyze:
1. CH3CHO (Acetaldehyde)
2. CO2 (Carbon Dioxide)
3. CO (Carbon Monoxide)
4. CO3^2- (Carbonate Ion)

### Step 2: Draw the Structures
- **CH3CHO**: This compound has a carbonyl (C=O) group. The C-O bond here is a double bond.

- **CO2**: In carbon dioxide, there are two C=O double bonds. Each C-O bond is also a double bond.

- **CO**: Carbon monoxide has a triple bond between carbon and oxygen (C≡O).

- **CO3^2-**: The carbonate ion has one C=O double bond and two C-O single bonds. However, due to resonance, the C-O bonds are not purely single or double; they are partial double bonds.

### Step 3: Analyze Bond Types
- **CH3CHO**: C-O bond is a double bond.
- **CO2**: C-O bonds are double bonds.
- **CO**: C-O bond is a triple bond.
- **CO3^2-**: The C-O bonds are partial double bonds due to resonance.

### Step 4: Compare Bond Lengths
The bond lengths are influenced by the type of bond:
- Single bonds are longer than double bonds.
- Double bonds are longer than triple bonds.
- Resonance structures can lead to bond lengths that are intermediate between single and double bonds.

### Step 5: Determine Maximum Bond Length
From the analysis:
- CH3CHO and CO2 have C-O double bonds.
- CO has a C-O triple bond, which is the shortest.
- CO3^2- has C-O bonds that are partial double bonds due to resonance, making them longer than pure double bonds.

### Conclusion
The maximum C-O bond length is found in the **CO3^2- (Carbonate Ion)** due to the presence of partial double bonds from resonance.

### Final Answer
The complex with the maximum C-O bond length is **CO3^2-**.

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