# How do you determine the number of pi and sigma bonds in a structure and locate them?

##### 1 Answer

#### Answer:

Using extended structure models

#### Explanation:

Here you have a more in-depth analysis of structure formulas.

Start off by writing down the respective compund using the extended structure model. Each **simple covalent bond** (represented by the line between 2 atoms) will be a **sigma bond** ;

Any other different from that ( double , triple covalent bonds ) will still have **one** sigma bond, the rest of the lines being counted as **pi bonds**

I'll give you an example:

Let's take the propane extended structure formula (which i stole from the answer above):

It is a **saturated** compound, so you will **only** have **simple** ( **sigma** ) **covalent bonds** - there are no **pi bonds**. Also, in this particular case ( for saturated aliphatic alkanes ) you can use a formula:

number of sigma bonds = number of atoms - 1 (which you can determine using the molecular formula )

If you would use that formula for propane, number of sigma bonds will be 3 + 8 - 1 = 10, as shown above.