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.
> $\text{ }\!\!\sigma\!\!\text{ }$ bonds are the strongest type of covalent bond. $\text{ }\!\!\sigma\!\!\text{ }$ bonds are formed by the head on overlapping atomic orbitals.
$\text{ }\!\!\pi\!\!\text{ }$ 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 $\text{ }\!\!\sigma\!\!\text{ }$ bond and 1 $\text{ }\!\!\pi\!\!\text{ }$ bond.
 > The triple bond has 1 $\text{ }\!\!\sigma\!\!\text{ }$ bond and 2 $\text{ }\!\!\pi\!\!\text{ }$ bonds.
And there are 2 non bonded electrons.
So in the given compound the number of $\text{ }\!\!\sigma\!\!\text{ }$ and $\text{ }\!\!\pi\!\!\text{ }$ bonds are 9 and 3 respectively with 2 non bonded electrons.
Therefore, Option C is the correct answer.

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

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