C5H9

C5H9 is the molecular formula for several organic compounds. This formula indicates that the molecule contains five carbon atoms and nine hydrogen atoms. These compounds are isomers of each other, meaning they have the same chemical formula but different structural arrangements. The presence of a deficiency of two hydrogen atoms compared to a saturated alkane with five carbons (C5H12, which is pentane) suggests that C5H9 compounds contain either one double bond or one ring structure within their carbon skeleton.

Common examples of compounds with the molecular formula C5H9 include pentenes and cyclopentane. Pentenes are alkenes with the double bond located at different positions along the five-carbon chain, such as 1-pentene, 2-pentene (which can exist as cis and trans isomers), and methylbutenes. Cyclopentane is a cyclic alkane where the five carbon atoms form a ring. Other structural isomers also exist. The specific properties and reactivity of a C5H9 compound depend entirely on its unique structural arrangement. These isomers are generally hydrocarbons and are flammable.