# How many geometric isomers exist for the molecule CH_3-CH=CH-CH=CH-CH_3?

Sep 23, 2016

There are three geometric isomers of hexa-2,4-diene.

#### Explanation:

The four possibilities are $\left(E , E\right)$, $\left(E , Z\right)$, $\left(Z , E\right)$, and $\left(Z , Z\right)$.

However, $\left(E , Z\right)$and $\left(Z , E\right)$ are identical.

$\left(2 E , 4 E\right) \text{-hexa-2,4-diene}$

$\left(2 E , 4 Z\right) \text{-hexa-2-4-diene}$

$\left(2 Z , 4 Z\right) \text{-hexa-2-4-diene}$