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    ok here is the marking point from the spec:

    understand that the fragmentation of a molecular ion
    M+• → X+ + Y•
    gives rise to a characteristic relative abundance spectrum
    that may give information about the structure of the
    molecule (rearrangement processes not required)

    could someone please explain what the relevance of the measure of relative abundance is?
    does it mean anything that can be used to determine the structure or is it just m/z that can be used for that?


    thannnnks♥
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    (Original post by Archen)
    ok here is the marking point from the spec:

    understand that the fragmentation of a molecular ion
    M+• → X+ + Y•
    gives rise to a characteristic relative abundance spectrum
    that may give information about the structure of the
    molecule (rearrangement processes not required)

    could someone please explain what the relevance of the measure of relative abundance is?
    does it mean anything that can be used to determine the structure or is it just m/z that can be used for that?


    thannnnks♥
    usually, organic chemists combine mass spec, IR, uv and NMR to deduce or confirm structures of organic compounds. the highest m/z value very often is the parent ion peak, ie it gives the molecular mass. measure of relative abundance is vital for calculating percentage of isotopes.
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    i have just read a bit that claims that the relative abundance is used as a way to directly compare spectra produced at different times or with different equipment..
    (i suppose sort of like the fingerprint region in IR) is this correct?
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    (Original post by Archen)
    i have just read a bit that claims that the relative abundance is used as a way to directly compare spectra produced at different times or with different equipment..
    (i suppose sort of like the fingerprint region in IR) is this correct?

    Yeah, I think it is. Relative abundances would differ depending on the sample, and therefore it can be used to make comparisons (like the fingerprint in infared).

    Are you on OCR chem, Archen?
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    (Original post by _Andrew_)
    Yeah, I think it is. Relative abundances would differ depending on the sample, and therefore it can be used to make comparisons (like the fingerprint in infared).

    Are you on OCR chem, Archen?
    _Andrew_! :hug:
    i havent seen you in a while!
    and no, AQA - its a bugger - LOADS of NMR and stuff. evil evil EVIL!

    thanks for the help btw
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    (Original post by Archen)
    _Andrew_! :hug:
    i havent seen you in a while!
    and no, AQA - its a bugger - LOADS of NMR and stuff. evil evil EVIL!

    thanks for the help btw

    Ahh. I'm doing OCR, and there is also tons of NMR! My exam is now in 13 days! Getting slightly worried, like:p:


    I've been stealing all the AQA past spectroscopy questions from an A level chem website :ninja:
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    (Original post by _Andrew_)
    Ahh. I'm doing OCR, and there is also tons of NMR! My exam is now in 13 days! Getting slightly worried, like:p:


    I've been stealing all the AQA past spectroscopy questions from an A level chem website :ninja:
    my exam is in 13 days too.
    AAAAAAAAAAAAAAAHHHHHHHHHHHHHHHH
    and i am asking stupid questions about mass spec and hanging out on TSR..

    must.get.off.internet.
 
 
 
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