Question

How many sigma bonds are present in naphthalene?

• A. 3
• B. 19
• C. 15
• D. 20

Answer 1

The correct option is B 19

Naphthalene has the molecular formula of $\left(C_{10}{H}_8\right)$.
$C-C$ bond formed is by the $p-p$ overlap between the two half filled $p$ -orbitals of the carbon atoms. There are a total of 11 $C-C$ bonds.
$C-H$ bond is formed by the $s-p$ overlap between the two half filled s orbital and $p$ -orbital of the Hydrogen and carbon atoms respectively. There are a total of 8 $C-H$ bonds.
So, it has 19 sigma bonds and 5 pi bonds.