Final answer:
Propane (C3H8) does not have any structural isomers. It can only exist in one form since its molecular formula allows for only a single arrangement of its carbon atoms.
Step-by-step explanation:
The compound C3H8 is known as propane.
When considering how many structural isomers this molecule has, we must consider the types of structural isomers possible, including chain isomers (where the carbon chain differs), positional isomers (differing positions of functional groups), and functional group isomers (different functional groups altogether).
Propane has a molecular formula that allows only a single arrangement of its carbon atoms— a straight chain of three carbons each fully saturated with hydrogen atoms.
No other structural arrangement can be made without altering the molecular formula.
Therefore, C3H8 does not have any structural isomers; it is the only structure possible for this molecular formula in terms of chain isomerism, positional isomerism, or functional group isomerism.