# How do you determine the number of structural isomers?

Mar 2, 2017

$\text{How else but by trial and error.......??}$

#### Explanation:

$\text{Butane can support 2 structural isomers.}$

$\text{Pentane}$ can support 3 structural isomers.

$\text{Hexane}$ can support 5 structural isomers.

$\text{Heptane}$ can support 9 structural isomers.

Even as an undergraduate, you would not be expected to know and represent all the structural isomers of hexane. You would be expected to be able to name a given isomer, and so differentiate between identical structures and isomers of a given formula.