Question

distinguish between ethylamine and acetamide

Answer 1

Acetamide with NaOH give Sodium acetate, whereas ethylamine does not react with NaOH.
$$\begin{gathered} C{H}_{3}CON{H}_2\stackrel{NaOH}{\to }C{H}_{3}COONa \\ AcetamideSodiumacetate \end{gathered}$$