question_answer

Among the following the most reactive towards alcoholic \[B{{(OH)}_{3}}\] is:

A) \[{{B}^{3+}}\]

B) \[O-H\]

C) \[B{{(OH)}_{3}}+{{H}_{2}}O\xrightarrow{{}}{{[B{{(OH)}_{4}}]}^{-}}+{{H}^{+}}\]

D) \[A{{g}^{+}}\]

Correct Answer: D

Solution :

Propyl bromide \[{{B}^{3+}}\]c is most reactive towards alcoholic \[O-H\], in the presence of which it gives propane by elimination reaction. The reason is that in it \[B{{(OH)}_{3}}+{{H}_{2}}O\xrightarrow{{}}{{[B{{(OH)}_{4}}]}^{-}}+{{H}^{+}}\] bond has maximum polarity. In vinyl bromide, (\[A{{g}^{+}}\] bond has partial double   bond   character   due   to delocalization lone pair of electron on \[C{{N}^{-}}\] atom.