What is the IUPAC name for a hydrocarbon with the formula C4H8?

The IUPAC name for a hydrocarbon with the formula C4H8 is butene. This compound is classified as an alkene, which is characterized by the presence of at least one double bond between carbon atoms.

In the case of butene, it specifically has four carbon atoms (indicated by "but-") and at least one double bond, which is denoted by the suffix "-ene." Butene can exist in several isomeric forms, such as 1-butene and 2-butene, depending on the location of the double bond.

Understanding the structure is key to identifying the name; C4H8 fits the general formula for alkenes, CnH2n, where "n" equals the number of carbon atoms in the chain. As there are four carbons, substituting n with 4 gives us the formula C4H8, confirming it as an alkene.

The other choices—propane, phenyl, and ethylene—either represent different types of hydrocarbons or do not correspond to the correct molecular formula. Propane is an alkane with the formula C3H8, phenyl is a cyclic compound related to benzene, and ethylene refers to