Which of the following statement is not true about carbonyl group :

Options

A. Carbon - oxygen bond is polarised due to higher electronegativity of oxygen
B. Carbonyl carbon is electrophilic while oxygen is nucleophilic center
C. Carbonyl group have more dipole moment then ether
D. Polarity of carbonyl group as given

Answer

To determine which statement is not true about the carbonyl group, we will analyze each of the provided options step by step.

### Step 1: Understanding the Carbonyl Group
The carbonyl group consists of a carbon atom double-bonded to an oxygen atom (C=O). The carbon atom in the carbonyl group is typically sp² hybridized, and the oxygen atom has two lone pairs of electrons.

### Step 2: Analyzing the Options
1. **Option 1: The carbon-oxygen bond is polarized due to the high electronegativity of oxygen.**
- **Analysis:** Oxygen is more electronegative than carbon, which means it attracts the shared electrons in the C=O bond more strongly. This results in a partial negative charge (δ-) on the oxygen and a partial positive charge (δ+) on the carbon. Therefore, this statement is true.

2. **Option 2: Carbonyl carbon is electrophilic while oxygen is a nucleophilic center.**
- **Analysis:** The carbon atom in the carbonyl group has a partial positive charge (δ+) and can attract nucleophiles (electron-rich species). The oxygen atom, with its lone pairs, can act as a nucleophile. Thus, this statement is also true.

3. **Option 3: Carbonyl group has more dipole moment than ether.**
- **Analysis:** The carbonyl group (C=O) has a significant dipole moment due to the electronegativity difference between carbon and oxygen. In ethers (R-O-R'), the oxygen is bonded to two carbon atoms and has a lower dipole moment compared to the carbonyl group. Therefore, this statement is true.

4. **Option 4: The polarity of the carbonyl group is such that it can break to give O- and a positive charge on carbon.**
- **Analysis:** This statement is misleading. While the carbonyl bond can undergo nucleophilic attack, it does not simply break to give O- and a positive charge on carbon in a straightforward manner. The carbon does not become positively charged in this context without a nucleophile attacking it first. Therefore, this statement is not true.

### Conclusion
Based on the analysis above, the statement that is not true about the carbonyl group is **Option 4**.

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