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Homework Help: Alkane Nomenclature

  1. Jan 27, 2010 #1
    1. This is my first posting, I am having trouble naming alkanes. I believe my first two problems are correct, but am unsure. The third problem I am having trouble with. I am just not sure what to name the branches coming off the carbon chain.



    2.

    1. (CH3)2CHCH(CH3)2


    2. CH2Ch2CH2CH3
    l
    CH3CH2CH2CHCH2C--H
    l l
    CH3CH2 H


    3.
    CH3 H
    l l
    CH3CH2CH2CH2--C--C--CH2CH3
    l l
    CH2 CH3
    l
    CH3




    3. Problem 1 :4-carbon chain makes it butane. The branches at both C2 and C3 are methyl, so the name is 2,3-dimethylbutane.

    Problem 2: 6-carbon chain makes it hexane. The branch at C2 is butyl. The branch at C3 is ethyl, so the name is 2-butyl-3-ethylbutane.

    Problem 3:
    8-carbon chain= octane
    branch at C3 is methyl
    branches at 4C are methyl and ethyl
    That is where I get stuck on the name. Is it 4-ethyl-4,3-dimethyloctane??

    Thanks very much for your input!
     
  2. jcsd
  3. Jan 27, 2010 #2
    I can't get the equations to display properly! I will edit as soon as I figure it out :)
     
  4. Jan 28, 2010 #3

    chemisttree

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    You have 1) correct.
     
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