How do I systematically name alkanes?

When naming alkanes, I like to follow a set of rules:Firstly, draw out the molecule structurally showing all bonds present. Next identify the longest carbon chain. The longest carbon chain determines the suffix of the molecule. If the carbon chain contains 1C, then the suffix will be methane, 2C= ethane, 3C=propane, 4C= butane, 5C= pentane, 6C= hexane.Next we look at the side groups, which will prefix the carbon chain. In the homologous series of alkanes alkyl groups may be present (side groups containing carbon and hydrogen only). If the alkyl group contains 1C, then it will be named methyl, 2C= ethyl, 3C= propyl etc..We must now state the position of the side group by giving it a number according to which carbon it is attached. To do this we need to look again at the longest carbon chain. We number the alkyl group with the smallest possible number on the carbon chain. The number of the alkyl group prefixes the molecule. Finally, if there is more than one of the same alkyl group present, then the alkyl group is prexifed by di or tri etc.Note! Numbers are separated by commas and numbers and letters are separated by a hyphen. eg. 2-methylpropane

Answered by Nora M. Chemistry tutor

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