Draw the structural formulas for three isomers of pentane, \(\mathrm{C}_{5} \mathrm{H}_{12} .\)

Draw a straight chain of 5 carbon atoms bonded to each other. This straight chain is known as n-pentane, where n denotes a normal (straight) chain. \(\mathrm{CH}_{3}\mathrm{-}\mathrm{CH}_{2}\mathrm{-}\mathrm{CH}_{2}\mathrm{-}\mathrm{CH}_{2}\mathrm{-}\mathrm{CH}_{3}\) There are no branches in this structure, and all carbon atoms are connected in a linear pattern.

In this isomer, we will create a branch in the carbon skeleton by moving one carbon atom from the end of the chain to the 2nd carbon atom position in the original pentane chain. This will form a new compound, isopentane (also known as 2-methylbutane). \(\mathrm{CH}_{3}\mathrm{-}\mathrm{CH\ (}\mathrm{CH}_{3})\mathrm{-}\mathrm{CH}_{2}\mathrm{-}\mathrm{CH}_{3}\) In this structure, there is a single branch on the second carbon atom, creating a new isomer.

For the third isomer, create two branches by moving two carbon atoms from the end of the original pentane chain to the 2nd carbon atom position. This will form the compound neopentane, also known as 2,2-dimethylpropane. \(\mathrm{C\ (}\mathrm{CH}_{3})_{4}\) In this structure, the central carbon atom is bonded to four methyl groups (\(\mathrm{CH}_3\)), creating another unique isomer of pentane. The three isomers of pentane are: 1. n-Pentane (\(\mathrm{CH}_{3}\mathrm{-}\mathrm{CH}_{2}\mathrm{-}\mathrm{CH}_{2}\mathrm{-}\mathrm{CH}_{2}\mathrm{-}\mathrm{CH}_{3}\)) 2. Isopentane (2-methylbutane): \(\mathrm{CH}_{3}\mathrm{-}\mathrm{CH\ (}\mathrm{CH}_{3})\mathrm{-}\mathrm{CH}_{2}\mathrm{-}\mathrm{CH}_{3}\) 3. Neopentane (2,2-dimethylpropane): \(\mathrm{C\ (}\mathrm{CH}_{3})_{4}\)