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    (Original post by _HabibaH_)
    The diazonium depends on its side chain function groups so 3-nitrodiazonium chloride or 4-methylphenyldiazonium chloride etc.
    I see and what about azo dyes?
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    (Original post by otrivine)
    I see and what about azo dyes?
    I don't think we need to know. Nowhere in the book or PP questions has it told us how to name or asked us for a name.
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    can someone summarise what I need to know on triglycerides, diet, and health please
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    (Original post by MathsNerd1)
    Okay, what changes the isoelectric point on an amino acid, I'm not sure if something like this could come up though.


    amino acids are amphoteric so could either act as a base or an acid? So, could act as a base and accept proton which becomes COO- as the H+ is lost from carboxyl group and could act as acid and donate a proton to the NH2 to become H3N+
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    (Original post by _HabibaH_)
    I don't think we need to know. Nowhere in the book or PP questions has it told us how to name or asked us for a name.
    Do we have to memorise on producing the chromatogram, its not in the syllabus?
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    (Original post by otrivine)
    amino acids are amphoteric so could either act as a base or an acid? So, could act as a base and accept proton which becomes COO- as the H+ is lost from carboxyl group and could act as acid and donate a proton to the NH2 to become H3N+
    Don't quote me on this but I always thought it was the number of amine groups which changed the isoelectric point, although I suppose it could work the same way with carboxylic acid groups.
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    (Original post by Raafae)
    In June 2010 paper for 1bi it says that the nitronium ion has to be substituted at a specific position on the benzene ring otherwise you get penalised. Does anyone know the rules for substitution onto the benzene ring

    Paper: http://www.ocr.org.uk/Images/59707-q...d-analysis.pdf
    Mark scheme: http://www.ocr.org.uk/Images/59704-m...lysis-june.pdf

    Thank you
    Look at the position of the N=N bond in sudan II
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    (Original post by MathsNerd1)
    Don't quote me on this but I always thought it was the number of amine groups which changed the isoelectric point, although I suppose it could work the same way with carboxylic acid groups.
    Good question, in the exam if they asked this ill put both in to be on the safe side, they dont contridict right
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    (Original post by Raafae)
    In June 2010 paper for 1bi it says that the nitronium ion has to be substituted at a specific position on the benzene ring otherwise you get penalised. Does anyone know the rules for substitution onto the benzene ring

    Paper: http://www.ocr.org.uk/Images/59707-q...d-analysis.pdf
    Mark scheme: http://www.ocr.org.uk/Images/59704-m...lysis-june.pdf

    Thank you
    Generally I don't think it matters, but in this question because we are given the end product all of the steps must agree with the structure of the end product. So because in the end product the -N=N- part on the benzene ring in opposite one methyl group and adjacent to another, then the NO2, NH2 and N=N groups must all also be in this position.
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    (Original post by otrivine)
    Do we have to memorise on producing the chromatogram, its not in the syllabus?
    If it's not on our syllabus then I don't see why we'd have to. But for understanding purposes, it wouldn't harm to learn it.
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    (Original post by otrivine)
    Good question, in the exam if they asked this ill put both in to be on the safe side, they dont contridict right
    I don't think so because one will increase it and the other would decrease it so they're both changing the isoelectric point really
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    (Original post by _HabibaH_)
    If it's not on our syllabus then I don't see why we'd have to. But for understanding purposes, it wouldn't harm to learn it.
    did you memorise the information on producing the chromarogram ?
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    (Original post by MathsNerd1)
    I don't think so because one will increase it and the other would decrease it so they're both changing the isoelectric point really


    true


    Did you memorise how to produce a chromatogram?
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    (Original post by otrivine)
    Good question, in the exam if they asked this ill put both in to be on the safe side, they dont contridict right
    no the isoelectric point depends on the R connected with the alpha carbon
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    (Original post by MathsNerd1)
    Don't quote me on this but I always thought it was the number of amine groups which changed the isoelectric point, although I suppose it could work the same way with carboxylic acid groups.
    I though the R group was only affected if it was in a solution of excess acid/base, but at the isoelectric point only one amine/carboxyl group would exchange H+
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    (Original post by _HabibaH_)
    I though the R group was only affected if it was in a solution of excess acid/base, but at the isoelectric point only one amine/carboxyl group would exchange H+
    Hmm, I'm not too sure sorry, it was a bad question to ask
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    (Original post by _HabibaH_)
    I though the R group was only affected if it was in a solution of excess acid/base, but at the isoelectric point only one amine/carboxyl group would exchange H+
    Yes.

    But the R group changes the isoelectric point.

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    (Original post by otrivine)
    true


    Did you memorise how to produce a chromatogram?
    From GC Erm ever so slightly remember it now but TLC is such an easier one to remember, besides half of it is common sense really
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    (Original post by amin666)
    no the isoelectric point depends on the R connected with the alpha carbon
    why is it the R group? is it because it determines the characterisitic properties of the amino acid
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    (Original post by rukan)
    1) halogeoalkane to alchol
    2)alchol + acid to ester
    3)notrobenzene to phnylamine
    4)halogenoalkane to amine

    THATS ALL I CAN REMEMBER
    Thanks
 
 
 
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