Provide the structures and names of the chain isomers of the molecular formula $C_6H_{14}$ that contain only a methyl group as a substituent.

(N/A) The molecular formula $C_6H_{14}$ corresponds to hexane. The chain isomers that contain only a methyl group as a substituent are as follows:

Structure	Name
$(i) \ CH_3-CH(CH_3)-CH_2-CH_2-CH_3$	$2\text{-methylpentane}$
$(ii) \ CH_3-CH_2-CH(CH_3)-CH_2-CH_3$	$3\text{-methylpentane}$