question_answer

Among the following compounds \[{{C}_{3}}{{H}_{7}}N{{H}_{2}},\] \[N{{H}_{3}},C{{H}_{3}}N{{H}_{2}},\]\[{{C}_{2}}{{H}_{5}}N{{H}_{2}}\] and \[{{C}_{6}}{{H}_{5}}N{{H}_{2}},\] the least basic compound is

A)                 \[{{C}_{3}}{{H}_{7}}N{{H}_{2}}\]               

B)                 \[N{{H}_{3}}\]

C)                 \[C{{H}_{3}}N{{H}_{2}}\]              

D)                 \[{{C}_{6}}{{H}_{5}}N{{H}_{2}}\]

E)                 \[{{C}_{2}}{{H}_{5}}N{{H}_{2}}\]

Correct Answer: D

Solution :

           \[{{C}_{6}}{{H}_{5}}N{{H}_{2}}\] is least basic compound due to resonance by which the Lone pair of nitrogen takes part in resonance & due to unavailability of lone pair on N Aniline become less basic. The Lone pair of N is delocalized into benzene ring by resonance