Question

How many sigma and pi bonds are present in buta-1-3-di-ene ?

Answer 1

Consider 1,3-butadiene,

Each double bond has one `pi` bond, and denoted by the structure, there are three `sigma` bonds between the carbons.

Moreover, each `C-H` bond constitutes another `sigma` bond. In this case there are 6.

Hence, this species has,

2 `pi` bonds, and
9 `sigma` bonds.

Answer 2

`9 sigma" and "2pi " bonds"`

Explanation:

As you can see, there are only two double bonds, which result in two `pi` bonds. The rest are all `sigma` bonds, including two from the double bonds.