Which one of the following does not have `sp^(2)` hybridised carbon ?

Options

A. Acetone
B. Acetic acid
C. Acetonitrile
D. Acetamide

Answer

To determine which compound does not have an sp² hybridized carbon, we will analyze the hybridization of carbon in each of the given compounds: acetone, acetic acid, acetonitrile, and acetamide.

### Step-by-Step Solution:

1. **Understanding sp² Hybridization**:
- Carbon atoms are sp² hybridized when they are involved in a double bond (C=C or C=O) or when they are bonded to three other atoms (two single bonds and one double bond).

2. **Analyzing Acetone**:
- The structure of acetone (C₃H₆O) is CH₃-CO-CH₃.
- The central carbon (C=O) is connected to two other carbon atoms and has a double bond with oxygen.
- Therefore, the central carbon in acetone is sp² hybridized.

3. **Analyzing Acetic Acid**:
- The structure of acetic acid (C₂H₄O₂) is CH₃-COOH.
- The carbon in the carboxylic group (C=O) is also connected to two other atoms (one carbon and one hydroxyl group).
- Hence, this carbon is also sp² hybridized.

4. **Analyzing Acetonitrile**:
- The structure of acetonitrile (C₂H₃N) is CH₃-C≡N.
- The carbon atom in the C≡N triple bond is sp hybridized, and the other carbon (CH₃) is sp³ hybridized.
- There are no sp² hybridized carbons in acetonitrile.

5. **Analyzing Acetamide**:
- The structure of acetamide (C₂H₅NO) is CH₃-CO-NH₂.
- The carbon in the carbonyl group (C=O) is connected to two other atoms (one carbon and one nitrogen).
- Thus, this carbon is sp² hybridized.

6. **Conclusion**:
- Among the compounds analyzed, **acetonitrile** does not have any sp² hybridized carbon. Therefore, the answer is **acetonitrile**.

### Final Answer:
**Acetonitrile does not have sp² hybridized carbon.**