Question

The IUPAC name of neopentane is,
A.$2 - $methylbutane
B.$2,2 - $dimethylpropane
C.$2 - $methylpropane
D.$2,2 - $dimethylbutane

Answer 1

Hint:IUPAC has proposed certain rules for the nomenclature of organic compounds. Therefore, every organic compound is named according to these rules.

Complete step by step answer: Neopentane is the common name of the molecule. The structure of neopentane molecule is,

The steps for naming a simple organic molecule like this are,
Identify the longest carbon chain.
Count the number of carbons in that chain and name according to that. For one carbon it is methane, for two carbon it is ethane, for three carbon it is propane etc.
Identify side chains or functional groups if present.
Position of the side chain(s) or functional group(s) should be mentioned in the name. For that, numbering is done following the priority order. While numbering multiple side chains, the one with least sum should be taken.
If multiple side chains of the same atom or group are present, a number of side chains should be mentioned using the prefixes di-, tri-,tetra etc.
Let’s name the given compound, neopentane.
The longest carbon chain contains three carbon atoms. Hence the parental chain is propane. There are two methyl groups present on the same carbon. These methyl groups are present on the second carbon. Numbering in any direction gives the same number to the carbon containing methyl group. Since two methyl groups are present, a prefix di- should be used before the name of the side chain. Hence the name of the compound is,
And hence the correct option is B.

Note:
Even though IUPAC names are given to all compounds, some are always called by their common name.A chemical nomenclature is a set of rules to generate systematic names for chemical compounds. The nomenclature used most frequently worldwide is the one created and developed by the International Union of Pure and Applied Chemistry (IUPAC).