Carbonyl Compounds

When ethyl bromide reacts with an ethanolic solution of ammonia, the reaction proceeds through a nucleophilic substitution mechanism. In this reaction:

1. Ethyl bromide (C₂H₅Br) acts as the substrate, which is an alkyl halide.
2. Ammonia (NH₃) in ethanolic solution serves as the nucleophile.
3. The nucleophile (NH₃) attacks the electrophilic carbon atom bonded to the bromine in ethyl bromide, replacing the bromide ion (Br^-).
4. This results in the formation of ethylamine (C₂H₅NH₂) and the release of a bromide ion.

The overall reaction can be represented as:

C₂H₅Br + NH₃ → C₂H₅NH₂ + HBr

This mechanism involves the substitution of the halide group by a nucleophile, confirming it as a nucleophilic substitution reaction.

Conclusion: The correct option is Nucleophilic substitution.