Question

The number of $\sigma$ bonds and $\pi$ bonds in the following structure respectively are:-

• A. $8,5$
• B. $8,6$
• C. $3,8$
• D. $5,13$

Answer 1

The correct option is A $8,5$

Sigma bond ($\sigma$-bond) is formed by head to head overlapping of atomic orbitals. It is the strongest type of covalent bond .

Example - Methane $\left(C{H}_4\right)$ has 4 sigma $\left(\sigma \right)$ bond between $C-H$ atom

Ref. image 1

It is known that all single bond is sigma bond while multiple bond is made of 1 sigma $\left(\sigma \right)$ bond and rest pi $\left(\pi \right)$ bond.

Given molecule is Ref. image 2

It is know that

single bond $=1\sigma$ bond

double bond $=1\sigma$ bond $+1\pi$ bond

triple bond $=1\sigma$ bond $+2\pi$ bond

The given compound has

$4$ single bond $=4\sigma$ bond

$3$ double bond $=3\sigma$ bond $+3\pi$ bond

$\underset{–}{1triplebond=1\sigma bond+2\pi bond}$

Total $=8\sigma$ bond $+5\pi$ bond

Therefore the given molecule has $8\sigma$ bond and $5\pi$ bond in total.