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    hi
    i know that alkane has no functional groups. but this question suddenly pops up in my mind. is 2,3-dimethylpentane an alkane as well? so far i only know alkanes have the general formula of C2H2n+2 and it works on this compound as well. but the structure of 2,3-dimethylpropane is completely different to the straight chain ones. please help.
    thanks
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    (Original post by kingsclub)
    hi
    i know that alkane has no functional groups. but this question suddenly pops up in my mind. is 2,3-dimethylpropane an alkane as well? so far i only know alkanes have the general formula of C2H2n+2 and it works on this compound as well. but the structure of 2,3-dimethylpropane is completely different to the straight chain ones. please help.
    thanks
    2,3-dimethylpropane does not exist, but methylbutane does
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    Alkanes can come in different shapes such as what you have mentioned.

    This is called Structural Isomerism- Hydrocarbons of the same formula but with different arrangements of atoms in space.

    Its usually done so that they have lower boiling points so can be combusted easier.

    In this case, 2,3-dimethylpropane is an isomer of pentane.
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    (Original post by Right Guard 3.D)
    Alkanes can come in different shapes such as what you have mentioned.

    This is called Structural Isomerism- Hydrocarbons of the same formula but with different arrangements of atoms in space.

    In this case, 2,3-dimethylpropane is an isomer of pentane.
    2,3-dimethylpropane does not exist, but methylbutane does
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    (Original post by charco)
    2,3-dimethylpropane does not exist, but methylbutane does
    sorry, i think i mean 2,3-dimethylpentane
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    (Original post by charco)
    2,3-dimethylpropane does not exist, but methylbutane does
    Yes

    I was looking at google images and just looking at the first picture and saw it had 5 carbons.

    I should pay more attention to detail.
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    (Original post by kingsclub)
    sorry, i think i mean 2,3-dimethylpentane
    Yes, it's a branched chain isomer of heptane
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    (Original post by charco)
    Yes, it's a branched chain isomer of heptane
    heptane!?
    may i ask how can you get 7 carbon atoms in the longest carbon chain? or is there another meaning of the term 'branched chain isomer'?
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    (Original post by kingsclub)
    heptane!?
    may i ask how can you get 7 carbon atoms in the longest carbon chain? or is there another meaning of the term 'branched chain isomer'?
    Are you familiar with the naming of branched isomers? And structural isomerism in general?

    Heptane is just a 7 carbon alkane in a long chain.

    With 2,3-dimethylpentane there are 7 carbons in total, and the overall forumula, like heptane is C7H16

    Since the longest chain is 5, it has pentane on the end of the name, and the 2 carbons branching off it are both as a methyl branch so its dimethyl.

    Does that help?
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    (Original post by Right Guard 3.D)
    Are you familiar with the naming of branched isomers? And structural isomerism in general?

    Heptane is just a 7 carbon alkane in a long chain.

    With 2,3-dimethylpentane there are 7 carbons in total, and the overall forumula, like heptane is C7H16

    Since the longest chain is 5, it has pentane on the end of the name, and the 2 carbons branching off it are both as a methyl branch so its dimethyl.

    Does that help?
    thanks.
    i thought the name 'heptane' only works on straight carbon chains but not branched ones...
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    (Original post by kingsclub)
    thanks.
    i thought the name 'heptane' only works on straight carbon chains but not branched ones...
    Here's a little nomenclature program we put together - it might help you out. Download, save, unzip and run.
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    (Original post by kingsclub)
    thanks.
    i thought the name 'heptane' only works on straight carbon chains but not branched ones...
    Thats correct, branched alkanes have different names. In this case, you say that 2,3-dimethylpentane is a branched isomer of heptane.

    Just like 2-methylbutane is a branched isomer of pentane.
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    (Original post by kingsclub)
    heptane!?
    may i ask how can you get 7 carbon atoms in the longest carbon chain? or is there another meaning of the term 'branched chain isomer'?
    He didn't say 7 carbon atoms is the longest carbon chain.

    What he is saying is that 2,3-dimethylpentane is an isomer of heptane (C7H16), because it has the same molecular formula (7 carbons and 16 hydrigens). But its name has the word "pentane" in it because C5 is the longest chain.

    The longest chain is what you use to name the compund. But the total number of carbons (7 in this case) tells you what that structure is an isomer of. If you start with n-heptane (just all 7 carbons in a straight chain) and then try to unplug it and reconnect it in different ways, you get to the isomers of heptane (of which 2,3-dimethylpentane is one.

    Do you see now?
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    wow, thanks a lot guys.
    by the way, what an interesting software you've got here! quite useful XD
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    random question, is it possible for an organic compound to have more than one functional group? i once heard a professor explaining the different functional groups of ketamine but i've checked on wiki and the only functional group is imine...
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    (Original post by kingsclub)
    random question, is it possible for an organic compound to have more than one functional group? i once heard a professor explaining the different functional groups of ketamine but i've checked on wiki and the only functional group is imine...
    certainly! Its extremely common for that to be the case. It's really only the very simplest compounds that only have one functional group. Amino acids are an example. They have both an amino group and a carboxylic acid group.
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    (Original post by kingsclub)
    random question, is it possible for an organic compound to have more than one functional group? i once heard a professor explaining the different functional groups of ketamine but i've checked on wiki and the only functional group is imine...
    Yep, at A2 chemistry you should learn about Amino Acids, they have an amino group (NH2) and Carboxylic acid group (COOH)
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    (Original post by Right Guard 3.D)
    Yep, at A2 chemistry you should learn about Amino Acids, they have an amino group (NH2) and Carboxylic acid group (COOH)
    SNAP!
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    thanks guys!
    its my pleasure to learn from all of you^^
 
 
 

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