the naming of organic compounds?

[hubert]

Hello!! i have a question...about the nomenclature of organic compounds...we should name ethyl first rather then methyl right? errr, however if the the methyl is replaced by a dimethyl, which comes first...the dimethyl or ethyl? in this case should we use the alphabetical order?

[opuntia]

ethyl would come first as dimethyl still represents the methyl group .
for example: CH3CH2CH(C2H5)C(CH3)(CH3)CH3
It has one ethyl group and two methyl groups and the IUPAC name for it is 3-ethyl-2,2-dimethylpentane.
Hope this helps