[Dillema103]

I have a task in which I need to draw a structural formula of 5-ethyl-hexane but I am not sure if that is possible as adding ethyl to the 5th carbon would add 2 additional ones making it a heptane. Does an alkyl not count towards the carbon chain making this possible as CH3CH2CH2CH2CH(CH2CH3)CH3, if not am I correct in assuming that it is not possible to complete this task?

[AWK]

According to nomenclature rules, only one ethyl-hexane exists - namely 3-ethyl-hexane.
Even for monosubstituted ethyl-heptanes, only locants 3- or 4- are possible (Rule: The locants are assigned such that the principal functional group gets the lowest possible locant).

[Dillema103]

According to nomenclature rules, only one ethyl-hexane exists - namely 3-ethyl-hexane.
Even for monosubstituted ethyl-heptanes, only locants 3- or 4- are possible (Rule: The locants are assigned such that the principal functional group gets the lowest possible locant).

Thanks for the answer. What would happen in a case where locants 2- 3- and 4- were all occupied? Would the ethyl go on the 5th locant then?

[AWK]

The first branch of carbon chain should have the lower locant - 2,4-dimethyl hexane (not 3,5-...), 3-ethyl-2,4-dimethyl hexane, 3-ethyl-2,5-dimethyl hexane, 3-ethyl-2,2,4-trimethyl hexane, 3-ethyl-2,4,5-trimethyl hexane.
4-Ethyl-2,2,3,3-tetramethyl hexane is the correct name.
Search for branched hydrocarbons nomenclature.

[Dillema103]

Much appreaciated!