Question

multiple choice—2 points. provide an acceptable iupac name for the alkane shown below. ch3—ch—ch2ch2ch(ch3)2 | ch2ch3. 2,5 - dimethylheptane. 2 - ethyl,5 - methylhexane. 2 - methyl,5 - ethylhexane. 3,6 - dimethylheptane

Explanation:

Step1: Identify the longest carbon - chain

The longest continuous carbon - chain has 7 carbon atoms, so the parent name is heptane.

Step2: Locate and name the substituents

There are two methyl ($-CH_3$) groups. One is on the 2nd carbon and the other is on the 5th carbon of the heptane chain. Following IUPAC rules for naming alkanes, we name it 2,5 - dimethylheptane. The other options are incorrect because:

• In 2 - ethyl,5 - methylhexane and 2 - methyl,5 - ethylhexane, the longest chain is mis - identified. If we consider these names, we are not choosing the longest continuous carbon - chain.
• 3,6 - dimethylheptane has the wrong numbering of the substituents. According to IUPAC rules, we number the chain to give the substituents the lowest possible numbers.

Answer:

A. 2,5 - dimethylheptane