Question

what is the name of this alkane?
1 - methylbutane
2 - methylbutane
1,2 - triethylethane
1 - dimethylpropane

Explanation:

Step1: Identify the longest carbon - chain

The longest continuous carbon - chain has 4 carbon atoms, so the parent alkane is butane.

Step2: Locate the substituent

There is a methyl ($-CH_3$) group attached to the second carbon atom of the butane chain.

Step3: Name the alkane

According to IUPAC naming rules for alkanes, the name is 2 - methylbutane.

Answer:

2 - methylbutane