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Any Difference between 'butene' and 'but-1-ene'? watch

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    The 1 just lets you know that the double bond is on the first carbon.

    Would you ever say butene independently?
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    (Original post by Mihael_Keehl)
    The 1 just lets you know that the double bond is on the first carbon.

    Would you ever say butene independently?
    No, you always write the 1 or else it's wrong.

    Is that what you're asking?
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    (Original post by TheonlyMrsHolmes)
    No, I think you always write the 1 or else it's wrong.

    Is that what you're asking?
    I think so?

    xD Organic chem at crack of dawn <3

    So butene does not exist? Can you get ethene on its own or would it be eth-1-ene?
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    (Original post by Mihael_Keehl)
    The 1 just lets you know that the double bond is on the first carbon.

    Would you ever say butene independently?
    Presuming this is for GCSE/A levels, I would just play it safe and call it But-1-ene. Rationale behind it is to have the ability to distinguish between say, But-1-ene & But-2-ene.

    Otherwise no, there's no difference.
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    (Original post by SA-1)
    Presuming this is for GCSE/A levels, I would just play it safe and call it But-1-ene. Rationale behind it is to have the ability to distinguish between say, But-1-ene & But-2-ene.

    Otherwise no, there's no difference.

    Thank you, great

    Would you say ethene or eth-1-ene?
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    (Original post by Mihael_Keehl)
    I think so?

    xD Organic chem at crack of dawn <3

    So butene does not exist? Can you get ethene on its own or would it be eth-1-ene?

    No, ethene is just ethene, because the double bond won't move or change. So no need to distinguish it. But with But-1-ene or But-2-ene, it has moved, do you see what I mean?
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    (Original post by Mihael_Keehl)
    Thank you, great

    Would you say ethene or eth-1-ene?
    Ethene would be a different case since there's no possiblity of the C=C to exist anywhere else.. so no, I would just call it ethene.
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    (Original post by TheonlyMrsHolmes)
    No, ethene is just ethene, because the double bond won't move or change. So no need to distinguish it. But with But-1-ene or But-2-ene, it has moved, do you see what I mean?
    (Original post by SA-1)
    Ethene would be a different case since there's no possiblity of the C=C to exist anywhere else.. so no, I would just call it ethene.
    Thannks just to clarify:

    Ethene is a special case.

    Then after that carbons that there are more of 3 you must name with respect to the double bond, i.e. 1,2 etc. and you always name from the first carbon you touch - i.e. double bond between 2 and 3 then it will be xxx-3-ene.

    I believe I understand you guys, you double this so you give each compound a specified name, so you can distinguish it in case of isomers etc. right?

    Thanks for your help.
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    (Original post by Mihael_Keehl)
    Thannks just to clarify:

    Ethene is a special case.

    Then after that carbons that there are more of 3 you must name with respect to the double bond, i.e. 1,2 etc. and you always name from the first carbon you touch - i.e. double bond between 2 and 3 then it will be xxx-3-ene.

    I believe I understand you guys, you double this so you give each compound a specified name, so you can distinguish it in case of isomers etc. right?

    Thanks for your help.
    I'm afraid your question has confused me what do you mean with the two parts I have highlighted, can you make it any clearer for me please?! and then maybe I can help you
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    (Original post by Mihael_Keehl)
    Thannks just to clarify:

    Ethene is a special case.

    Then after that carbons that there are more of 3 you must name with respect to the double bond, i.e. 1,2 etc. and you always name from the first carbon you touch - i.e. double bond between 2 and 3 then it will be xxx-3-ene.

    I believe I understand you guys, you double this so you give each compound a specified name, so you can distinguish it in case of isomers etc. right?

    Thanks for your help.
    Double bond between a second and third carbon would be xxx-2-ene, not 3-ene. You number the first carbon affected. xxx-3-ene would be the double bond between the third and fourth (providing this goes higher than four carbons).

    So..

    Ethene: C=C

    Prop-1-ene: C=C-C

    But-1-ene: C=C-C-C or C-C-C=C

    But-2-ene: C-C=C-C

    Pent-1-ene: C=C-C-C-C

    Pent-2-ene: C-C=C-C-C or C-C-C=C-C

    Hex-1-ene: C=C-C-C-C-C

    Hex-2-ene: C-C=C-C-C-C or C-C-C-C=C-C

    Hex-3-ene: C-C-C=C-C-C

    But yeah apart from that you're right. Isomers and being able to identify more complex structures too.. you'll learn as you go on.
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    (Original post by TheonlyMrsHolmes)
    I'm afraid your question has confused me what do you mean with the two parts I have highlighted, can you make it any clearer for me please?! and then maybe I can help you
    Sorry,

    So you can't get methene.

    Ethene is the only possible type of alkene.

    Then the naming process begins, of double bonds depending on where the carbon atom is since there are more than 2 carbon atoms.

    I don't know what double means either ffs. Sorry.
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    (Original post by SA-1)
    Double bond between a second and third carbon would be xxx-2-ene, not 3-ene. You number the first carbon affected. xxx-3-ene would be the double bond between the third and fourth (providing this goes higher than four carbons).

    So..

    Ethene: C=C

    Prop-1-ene: C=C-C

    But-1-ene: C=C-C-C or C-C-C=C

    But-2-ene: C-C=C-C

    Pent-1-ene: C=C-C-C-C

    Pent-2-ene: C-C=C-C-C or C-C-C=C-C

    Hex-1-ene: C=C-C-C-C-C

    Hex-2-ene: C-C=C-C-C-C or C-C-C-C=C-C

    Hex-3-ene: C-C-C=C-C-C

    But yeah apart from that you're right
    Thank you that is what I meant, sorry!

    Finally last question on this for something like hex-1-ene in your example
    :

    It can be: Hex-1-ene: C-C-C-C-C=C too right?

    And ethene is the only alkene without a number attached to it, since there is no choice for where the double bond must lie.

    Therefore you can't get hexene?

    Thanks for your effort
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    (Original post by Mihael_Keehl)
    Thank you that is what I meant, sorry!

    Finally last question on this for something like hex-1-ene in your example
    :

    It can be: Hex-1-ene: C-C-C-C-C=C too right?

    And ethene is the only alkene without a number attached to it, since there is no choice for where the double bond must lie.

    Therefore you can't get hexene?

    Thanks for your effort
    Essentially yes.

    I'd argue Propene too, but that's something you should confirm with a teacher because I'm not sure what the mark schemes ask for nowadays.

    As compounds become more complex, it becomes important to identify the double bonds. So when more elements or methyl groups are added - numbering becomes even more important.

    Remember the basics and stick to that, when you come across the more complicated ones these should make sense.

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    (Original post by Mihael_Keehl)
    Sorry,

    So you can't get methene.

    Ethene is the only possible type of alkene.

    Then the naming process begins, of double bonds depending on where the carbon atom is since there are more than 2 carbon atoms.

    I don't know what double means either ffs. Sorry.

    Here, this might help you!

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    and

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    Thanks guys, really improved my understanding.

    So for something such as:

    methylpropane:


    Where is the methyl group because CH3 CH2 CH2 CH3 is just butane, how am I supposed to know where it goes without a number associated with it. Thanks.

    (Original post by SA-1)
    Essentially yes.

    I'd argue Propene too, but that's something you should confirm with a teacher because I'm not sure what the mark schemes ask for nowadays.

    As compounds become more complex, it becomes important to identify the double bonds. So when more elements or methyl groups are added - numbering becomes even more important.

    Remember the basics and stick to that, when you come across the more complicated ones these should make sense.

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    (Original post by TheonlyMrsHolmes)
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    (Original post by Mihael_Keehl)
    Thanks guys, really improved my understanding.

    So for something such as:

    methylpropane:


    Where is the methyl group because CH3 CH2 CH2 CH3 is just butane, how am I supposed to know where it goes without a number associated with it. Thanks.


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    There isn't, I meant to say that in the future when you come across them you'll need to be able to name and identify these double bonds correctly.

    Wouldn't worry about it now tbh

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    (Original post by SA-1)
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    There isn't, I meant to say that in the future when you come across them you'll need to be able to name and identify these double bonds correctly.

    Wouldn't worry about it now tbh

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    Right yes, thanks.

    But for the example of Methylpropane: Would it be: CH3-CH(CH3)-CH3
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    (Original post by Mihael_Keehl)
    Right yes, thanks.

    But for the example of Methylpropane: Would it be: CH3-CH(CH3)-CH3
    That would be 2-methylpropane.

    Because you could have (for example) 1-bromo, 2-methylpropane if you were to add a bromine group to the first carbon right? So you need to be specific for anything above ethane

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    (Original post by SA-1)
    That would be 2-methylpropane.

    Because you could have (for example) 1-bromo, 2-methylpropane if you were to add a bromine group to the first carbon right? So you need to be specific for anything above ethane

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    Understood thank you again.
 
 
 
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