Final answer:
Three structural isomers of C5H12 include n-pentane, isopentane (2-methylbutane), and neopentane (2,2-dimethylpropane). The IUPAC name for the isomer with a five-carbon chain is n-pentane.
Step-by-step explanation:
The student has asked to draw and name three structural isomers with the formula C5H12, as well as to specifically draw the isomer with a five carbon atoms main chain. Structural isomers are molecules that have the same molecular formula but different structural arrangements of atoms.
The isomer with five carbon atoms in the main chain is n-pentane. Its IUPAC name is simply pentane. The other two structural isomers of C5H12 are isopentane and neopentane. Isopentane, with a four carbon main chain and a methyl substituent, is also known as methylbutane or 2-methylbutane. Neopentane, with three methyl groups on the second carbon of a three-carbon chain, is also known as dimethylpropane or 2,2-dimethylpropane.
IUPAC Names of C5H12 Isomers
Pentane (n-pentane)
Isopentane (2-methylbutane)
Neopentane (2,2-dimethylpropane)
To draw the isomer with five carbon atoms in the main chain (n-pentane), simply arrange five carbon atoms in a straight line with sufficient hydrogens to satisfy each carbon atom's four bonds.