What is the IUPAC name for CH3-CH(CH3)-CH2-CH3?

The molecule CH3-CH(CH3)-CH2-CH3 can be systematically named by identifying the longest continuous carbon chain and the substituents present.

In this structure, the longest chain consists of five carbon atoms, making it a pentane. Numbering the chain starts from one end, which results in the following sequence: CH3 (1) - CH (2) - CH2 (3) - CH2 (4) - CH3 (5). The methyl (CH3) group is attached to the second carbon of the chain.

Therefore, the correct IUPAC name for this compound is 2-Pentane, indicating that the methyl substituent is located on the second carbon of the five-carbon chain. The naming follows the IUPAC conventions for organic molecules, ensuring that chains are numbered so that substituents receive the lowest possible numbers.

The other choices do not accurately describe the structure present. 2-Butane, for instance, has only four carbons, making it incorrect for this five-carbon compound. 3-Pentane suggests that a substituent would be on the third carbon when in actuality it is on the second. Lastly, 2-Hexane indicates a six-carbon