How is acetic acid converted separately to methylamine and ethyl amine? 

Explanation

On heating with ammonia , acetic acid gives acetamide . Acetamide on heating with bromine in presence of `NaOH` gives methyl amine and on reduction with `LiAlH_(4)` gives ethyl amine .
`CH_(3) CO NH_(2) overset(Br_(2)) underset(NaOH)(to) CH_(3) NH_(2)`
`CH_(3) CO NH_(2) overset(LiAlH_(4))(to) CH_(3) CH_(2) NH_(2)`