Question

Allyl isocyanide has:
(A) 9σ and 4π – bonds
(B) 8σ and 5π – bonds
(C) 9σ, 3π and 2 non – bonded electron
(D) 8σ, 3π and 4 non – bonded electron

Answer 1

Hint: The molecular formula of Allyl isocyanide is $${\text{C}}_{\text{4}}{\text{H}}_{\text{4}}\text{N}$$. The molecular weight of Allyl isocyanide is $$\text{67}\text{.09g/mol}$$.
Step by step answer:

Allyl isocyanide can also be written as $$\text{C}{\text{H}}_{\text{2}}\text{=CH}\text{C}{\text{H}}_{\text{2}}\text{N}\equiv \text{C}$$.
We can see that in the given compound there are seven single bonds, one double bond and one triple bond.
> $\sigma$ bonds are the strongest type of covalent bond. $\sigma$ bonds are formed by the head on overlapping atomic orbitals.
$\pi$ bonds are covalent bonds in which the two lobes of an orbital on one atom overlap two lobes of an orbital on another atom and this overlap occurs laterally.
> The double bond has 1 $\sigma$ bond and 1 $\pi$ bond.
 > The triple bond has 1 $\sigma$ bond and 2 $\pi$ bonds.
And there are 2 non bonded electrons.
So in the given compound the number of $\sigma$ and $\pi$ bonds are 9 and 3 respectively with 2 non bonded electrons.
Therefore, Option C is the correct answer.

Additional Information: $\sigma$ bonds results from the head on overlap of the two orbitals of the two atoms, which has more area of overlap than the $\pi$ bonds which result from the parallel overlap of orbitals. That is why $\sigma$ bonds are stronger than $\pi$ bonds.

Note: The formula to calculate $\sigma$ bonds is: $$\text{X+Y-1}$$
Where,
$$\text{X = Number of Carbon atoms}$$
$$\text{Y = Number of Hydrogen atoms}$$
The formula to calculate $\pi$ bonds is: $$\left[\left\{{\displaystyle \frac{\left(\text{2X-Y}\right)}{\text{2}}}\right\}\text{+1}\right]$$
Where,
$$\text{X = Number of Carbon atoms}$$
$$\text{Y = Number of Hydrogen atoms}$$