Question

Find the number of sigma and pi bonds in ethyne molecule.

Answer 1

In the molecule of Ethyne as shown below:

$H-C\equiv C-H$
$1$ lobe interaction gives $1$ sigma bond
$2$ Head to head interaction gives $2$ sigma bonds
Total sigma bonds $\sigma =3$
$2$ side wise interaction gives $2$ pi bonds.
Total pi bonds $\pi =2$