Question

IUPAC name of chain isomer of butane is:

• A. 2-methylpropane
• B. n-butane
• C. isobutane
• D. butane

Answer 1

The correct option is A 2-methylpropane

IUPAC name of chain isomer of butane is 2-methylpropane. The longest chain has 3 C atoms and one methyl substituent.
The common name of chain isomer of butane is isobutane.
Chain isomers of alkanes have same molecular formula but different arrangement of carbon skeleton. n-butane has straight chain of carbon atoms. In iso-butane,the carbon chain is branched.