What is the correct IUPAC name for the following structure: ${\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{CH}}_2-{\mathrm{CH}}_3$?

• A. Butane
• B. Propane
• C. Pentane
• D. Methane

Answer: (A)

Verified step by step guidance

1. Identify the molecular formula of the given structure by counting the number of carbon (C) and hydrogen (H) atoms. The structure shows a chain of four carbon atoms connected linearly, each bonded to the appropriate number of hydrogens to satisfy carbon's tetravalency.
2. Determine the longest continuous carbon chain in the molecule. Since there are four carbon atoms connected in a row, the longest chain length is four.
3. Recall the IUPAC nomenclature for alkanes based on the number of carbon atoms in the longest chain: 1 carbon = Methane, 2 carbons = Ethane, 3 carbons = Propane, 4 carbons = Butane, 5 carbons = Pentane, and so on.
4. Since the longest chain has four carbons and there are no branches or functional groups, the molecule is a straight-chain alkane with four carbons, which corresponds to the name 'Butane'.
5. Confirm that there are no substituents or functional groups that would modify the base name. Since none are present, the correct IUPAC name is simply 'Butane'.