Question

part a
(a) $h_2c - ch_2 - ch_2 - ch_3$
$\

$$\begin{array}{l}ch_2 \\\\ | \\\\ ch_3 \\end{array}$$

$
2 - ethyl - butane
spell out the full name of the compound.

Explanation:

Step1: Find the longest carbon chain

The longest carbon chain has 5 carbon atoms (not 4 as in the incorrect name 2 - ethyl - butane).

Step2: Identify the substituent

There is a methyl group ($\text{CH}_3$) on the second carbon atom.

Step3: Name the compound

The compound is named according to the IUPAC rules. The parent chain is pentane (5 - carbon alkane) and the substituent is methyl at the second carbon.

Answer:

2 - methyl - pentane