Arrange the following compounds in increasing order of their reactivity in nucleophilic addition reactions.
(i) Ethanal, Propanal, Propanone, Butanone.
(ii) Benzaldehyde, p-Tolualdehyde, p-Nitrobenzaldehyde, Acetophenone.
Hint: Consider steric effect and electronic effect.

Explanation

To arrange the given compounds in increasing order of their reactivity in nucleophilic addition reactions, we need to consider both steric effects and electronic effects. Let's analyze each set of compounds step by step.

### (i) Ethanal, Propanal, Propanone, Butanone

1. **Identify the structures**:
- Ethanal (CH3CHO)
- Propanal (CH3CH2CHO)
- Propanone (CH3COCH3)
...