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    CH2=CH-CH=CH2

    CH3-C(triple bond)C-CH3

    HO-CH2-CH2-OH

    CH2Cl2

    I don't have a clue- help please :eek: :eek: :eek:
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    The first thing to do is identify the carbon chain:

    In the first one there are 4 carbons in the longest (only) chain ---> 'butane'

    Then lok for functional groups:

    you have double bonds ---> 'butene'

    you have two double bonds ---> 'butadiene'

    Finally put in the numbers that identify where the double bonds are (use the lowest numbers possible) ---> 1,3-butadiene
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    following on from the post before me, the second molecule is an alkyne, the third a diol (like di-alcohol) and the last is a halogenoalkane

    http://en.wikipedia.org/wiki/Alkyne
    http://en.wikipedia.org/wiki/Diol
    http://en.wikipedia.org/wiki/Halogenoalkane

    ^ these might help as well
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    (Original post by Elm_lily)
    CH2=CH-CH=CH2

    CH3-C(triple bond)C-CH3

    HO-CH2-CH2-OH

    CH2Cl2

    I don't have a clue- help please :eek: :eek: :eek:
    The answers are in spoiler tags if you want, but try and do these yourself. The most important thing is to count up the number of carbon atoms (1C-meth; 2C- eth, 3C- prop etc.), see if there are any double bonds/triple bonds/functional groups to identify the family, and then number the double bonds/triple bonds/functional groups and branches if there are any. It's a pain, but once you have naming hydrocarbons under your belt, you'll sail through it in the exam.

    1) A compound with one double bond ends with "-ene", and it follows that a compound with two double bonds ends with "-diene". You should be able to go from there. Remember to write in the numbers to show the position of the double bonds.

    Spoiler:
    Show
    1,3-butadiene


    2) Compounds with a triple bound belong to the alkyne family, and thus end in -yne. Remember to indicate the position of the triple bond.

    Spoiler:
    Show
    alk-2-yne but-2-yne


    3) We established one double bonds is an "-ene" and two double bonds is a "-diene" . Now if a compound with one O-H functional group ends in "-ol" (i.e. ethanol) what do you think a compound with two O-H functional groups will end in?

    Spoiler:
    Show
    1,2-ethanediol


    4) If a hydrocarbon has a halogen atom attached to it, you add "fluoro" "chloro", "bromo" or "iodo" depending on which halogen it is to the front of the name. Remember there are two chlorine atoms.

    Spoiler:
    Show
    dichloromethane
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    (Original post by innerhollow)
    The answers are in spoiler tags if you want, but try and do these yourself. The most important thing is to count up the number of carbon atoms (1C-meth; 2C- eth, 3C- prop etc.), see if there are any double bonds/triple bonds/functional groups to identify the family, and then number the double bonds/triple bonds/functional groups and branches if there are any. It's a pain, but once you have naming hydrocarbons under your belt, you'll sail through it in the exam.

    1) A compound with one double bond ends with "-ene", and it follows that a compound with two double bonds ends with "-diene". You should be able to go from there. Remember to write in the numbers to show the position of the double bonds.

    Spoiler:
    Show
    1,3-butadiene


    2) Compounds with a triple bound belong to the alkyne family, and thus end in -yne. Remember to indicate the position of the triple bond.

    Spoiler:
    Show
    alk-2-yne


    3) We established one double bonds is an "-ene" and two double bonds is a "-diene" . Now if a compound with one O-H functional group ends in "-ol" (i.e. ethanol) what do you think a compound with two O-H functional groups will end in?

    Spoiler:
    Show
    1,2-ethandiol


    4) If a hydrocarbon has a halogen atom attached to it, you add "fluoro" "chloro", "bromo" or "iodo" depending on which halogen it is to the front of the name. Remember there are two chlorine atoms.

    Spoiler:
    Show
    dichloromethane
    Thank you so much... I looked at the spoilers to check after reading your "hints". The only one I don't understand is alk-2-yne... but the rest are fine
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    I'm sure he meant but-2-yne :yep:
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    (Original post by Elm_lily)
    Thank you so much... I looked at the spoilers to check after reading your "hints". The only one I don't understand is alk-2-yne... but the rest are fine
    Oh um that's cos it's wrong lol. I meant but-2-yne sorry. Now I'll be able to make sure I don't do that in my exam!
 
 
 
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