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