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    What type of reaction is isomerisation? Neither my syllabus states anything about it nor any text book of A level tells that isomerisation is any kind of reaction! But the past papers gives this question and the mark scheme states its answer as C, i.e Isomerisation...
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    If two different compounds have the same molecular formula, then they are isomers of each other
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    Looks to me as if the fluorine on the 1st Carbon has swapped with the chlorine on the 2nd Carbon.

    The molecular formula of the molecule will not have changed. The structural formula has. Isomers are molecules with the same molecular formulae but different structural formulae.
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    (Original post by EierVonSatan)
    If two different compounds have the same molecular formula, then they are isomers of each other

    (Original post by mobius323)
    Looks to me as if the fluorine on the 1st Carbon has swapped with the chlorine on the 2nd Carbon.

    The molecular formula of the molecule will not have changed. The structural formula has. Isomers are molecules with the same molecular formulae but different structural formulae.
    Oh, wow. Thanks - I didn't even notice that. Btw isomerisation isn't any TYPE of reaction, right?
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    (Original post by Zishi)
    Oh, wow. Thanks - I didn't even notice that. Btw isomerisation isn't any TYPE of reaction, right?
    well bonds are broken and bonds are formed, so i would consider it to be so.
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    (Original post by shengoc)
    well bonds are broken and bonds are formed, so i would consider it to be so.
    Hmm, thanks. I got it. :yay:
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    (Original post by Zishi)
    Oh, wow. Thanks - I didn't even notice that. Btw isomerisation isn't any TYPE of reaction, right?
    It's a tricky one, because (and this is just a hunch, but it makes sense), in the reaction above for example, a C-F bond is broken and a C-Cl bond is broken. Now after that, a C-Cl bond is made in place of the broken C-F bond, and a C-F bond is made in place of the C-Cl bond.

    I'd say it's a reaction, yeah.
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    (Original post by mobius323)
    It's a tricky one, because (and this is just a hunch, but it makes sense), in the reaction above for example, a C-F bond is broken and a C-Cl bond is broken. Now after that, a C-Cl bond is made in place of the broken C-F bond, and a C-F bond is made in place of the C-Cl bond.

    Now, going back to the dreaded Energetics (more precisely, bond enthalpies), you should know that making bonds is exactly as exothermic and breaking bonds is endothermic. This meant that the Enthalpy Change of Reaction would be zero. This would mean total energy in = total energy out.

    I'd say it's a reaction, yeah.
    I don't think the assumption is neccesaily true. Diffferent groups bonded to a C atom will change the bond energy of other groups attached to the same C atom. For example, the C-H bond energy in choloromethane is different to the C-H bond in methane.
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    (Original post by Maker)
    I don't think the assumption is neccesaily true. Diffferent groups bonded to a C atom will change the bond energy of other groups attached to the same C atom. For example, the C-H bond energy in choloromethane is different to the C-H bond in methane.
    Hmmm, perhaps. If you model each Carbon as a seperate molecule, then I can see what you're talking about. I can see how the polarisation of the Carbon atoms would be different.
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    As said above, the molecular formula is the same for each compound. They are structural isomers of each other. I don't think the enthalpy change of the reaction will be zero either because the environment of the C-Cl bond in C-Cl3-C and CCl2F-C are different which would effect how the carbon atom attracts electrons and therefore the enthalpy of the bond
 
 
 
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