question_answer

Which of the following species contains equal number of \[\sigma \] and \[\pi \]-bonds?                             

A)  \[HCO_{3}^{-}\]              

B)  \[Xe{{O}_{4}}\]               

C)  \[{{(CN)}_{2}}\]              

D)  \[C{{H}_{2}}{{(CN)}_{2}}\]

Correct Answer: B

Solution :

	Structure	\[\sigma \] and \[\pi \] bonds
(a)		\[\sigma \] bond - 4 \[\pi \] bond-1
(b)		\[\sigma \]bond-4 \[\pi \] bond-4
(c)	\[N\equiv C-C\equiv N\]	\[\sigma \] bond-3 \[\pi \] bond-4
(d)	\[N\equiv 2C-\underset{\begin{smallmatrix}  \,\,| \\  H \end{smallmatrix}}{\overset{\begin{smallmatrix}  H \\  \,\,| \end{smallmatrix}}{\mathop{C}}}\,-C\equiv N\]	\[\sigma \] bond-6 \[\pi \] bond-4