Give hybridisation state of each carbon atom in the following molecules :
(i) `CH_3 - CH = CH_2`
(ii) `CH_2 = C = O`
(iii) `CH_2 = CHCN`
(iv) `HCONH_2`

Explanation

To determine the hybridization state of each carbon atom in the given molecules, we will analyze the bonding of each carbon atom based on the number of sigma (σ) and pi (π) bonds they form.

### (i) `CH3 - CH = CH2`

1. **First Carbon (C1)**:
- Structure: CH3
- Bonds: 4 σ bonds (3 with H and 1 with C2)
- Hybridization: **sp³**
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