What is the IUPAC name of the hydrocarbon with the molecular formula $C_5{H}_{12}$?

• A. 2,2-Dimethylpropane
• B. Hexane
• C. 2-Methylbutane
• D. Pentane

Answer: (D)

Verified step by step guidance

1. Identify the molecular formula given: \(C_5H_{12}\). This formula corresponds to an alkane with 5 carbon atoms and no double or triple bonds.
2. Recall that alkanes follow the general formula \(C_nH_{2n+2}\). For \(n=5\), the formula is \(C_5H_{12}\), confirming it is a saturated hydrocarbon (alkane).
3. Determine the longest continuous carbon chain in the molecule. Since the formula is \(C_5H_{12}\), the longest chain has 5 carbons, which corresponds to the parent name 'pentane'.
4. Check for any branches or substituents. If there are none, the compound is simply named after the longest chain, which is 'pentane'.
5. Verify that the other options (2,2-dimethylpropane, hexane, 2-methylbutane) either have different carbon counts or branching patterns that do not match the molecular formula \(C_5H_{12}\) as a straight chain.