Final answer:
The correct structural formula for butane is A) H₃C—CH₂—CH₂—CH₃. Butane is a straight-chain alkane with the general formula CnH2n+2, where for butane n=4, resulting in C4H10.
Step-by-step explanation:
The correct displayed (structural) formula for one molecule of butane (C4H10) is A) H₃C—CH₂—CH₂—CH₃. Butane is an alkane which means it has single bonds only and is represented by the general formula CnH2n+2. For butane, where n=4, it fits the formula C4H10. The structure of butane can be shown as a straight chain of four carbon atoms, with each carbon atom having the appropriate number of hydrogen atoms to complete its four bonds. This structure is referred to as n-butane. There is also another structural isomer called 2-methylpropane or isobutane, which shares the same molecular formula (C4H10) but has a different spatial arrangement of atoms.