Question

What is the IUPAC name of the compound: CH\(_3\) – CH\(_2\) – CH(CH\(_3\)) – CH\(_2\) – CH\(_3\)

• A. 3-Methylpentane
• B. 2-Methylpentane
• C. 3-Methylbutane
• D. 2-Methylbutane

Hint:

Always double-check if there is a longer chain "hiding" in a bend. In this case, the straight line is the longest, but in some structures, the chain might turn a corner!

Answer 1

The Correct Option is A

Step 1: Understanding the Concept
IUPAC nomenclature requires identifying the longest continuous carbon chain, numbering it to give the substituents the lowest possible positions, and naming the substituents alphabetically.

Step 2: Detailed Explanation
1. Identify the longest chain: The longest continuous chain of carbon atoms contains 5 carbons. The parent alkane is therefore "pentane." 2. Number the chain: Numbering from either left to right or right to left gives the substituent the same position: - C1(CH\(_3\)) - C2(CH\(_2\)) - C3(CH) - C4(CH\(_2\)) - C5(CH\(_3\)) 3. Identify the substituent: There is a methyl group (\(-CH_3\)) attached to the third carbon. 4. Combine: The position (3) + substituent (methyl) + parent (pentane) = 3-Methylpentane.

Step 3: Final Answer
The IUPAC name is 3-Methylpentane.