During the reaction :
`CH_3 CONH_2 overset(P_2 O_5)(to) CH_3 CN`
the hybridisation state of carbon changes from

Options

A. `sp^3` to `sp`
B. `sp^3` to `sp^2`
C. `sp^2` to `sp^3`
D. `sp^2` to `sp`

Answer

To determine the change in hybridization state of carbon during the reaction from CH₃CONH₂ to CH₃CN, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactant and Product**:
- The reactant is CH₃CONH₂ (Acetamide).
- The product is CH₃CN (Acetonitrile).

2. **Analyze the Structure of the Reactant (CH₃CONH₂)**:
- The structure of CH₃CONH₂ can be represented as:
```
H H
\ /
C
/ \
H C=O
|
N-H
```
- In this structure, the carbon atom (C) attached to the carbonyl group (C=O) is sp² hybridized because it forms three sigma bonds (one with the carbon in CH₃, one with the oxygen in C=O, and one with the nitrogen in NH₂) and one pi bond (in the C=O double bond).

3. **Analyze the Structure of the Product (CH₃CN)**:
- The structure of CH₃CN can be represented as:
```
H H
\ /
C
/ \
H C≡N
```
- In this structure, the carbon atom (C) attached to the nitrogen in the CN group is sp hybridized because it forms one sigma bond with the carbon in CH₃ and two pi bonds with the nitrogen in the triple bond (C≡N).

4. **Determine the Change in Hybridization**:
- The hybridization of the carbon in CH₃CONH₂ is sp².
- The hybridization of the carbon in CH₃CN is sp.
- Therefore, the change in hybridization state of carbon during the reaction is from sp² to sp.

5. **Conclusion**:
- The hybridization state of carbon changes from sp² in CH₃CONH₂ to sp in CH₃CN.

### Final Answer:
The hybridization state of carbon changes from sp² to sp.