Question

What does the number prefix tell you in the name of a branched alkane?

Answer 1

The number prefix reveals the location, and number of substituents attached to the longest carbon chain

Explanation:

The name of every alkane molecule has three parts:

prefix + parent + suffix

The parent name `->` indicates the number of the longest continuous carbon chain of the molecule.

The prefix `->` reveals the identity, location, and number of substituents attached to the longest carbon chain.

The suffix `->` indicates that the organic molecules you're dealing with is an alkane...

Example

2, 3-dimethylpentane

The numbers 2 and 3 indicate the position of the substituents on the longest continuous carbon chain.

Two numbers exist `=>` two substitutents are present on the parent carbon chain.