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OCR A2 CHEMISTRY F324 and F325- 14th and 22nd June 2016- OFFICIAL THREAD watch

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    (Original post by anndz3007)
    where do you put the charge on A ?? i thought nothing break down so i just leave it neutral ??
    My diester was a cyclic compound do you think that would be acceptable
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    (Original post by President J)
    I doubt it.
    check the book page 95, the 2 NMR with and without D2O, the only thing that changed is the presence of the O peak
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    (Original post by maisym00)
    Oh god, I wrote about them being photobiodegradavle on exposure to UV😕 Oops
    I mentioned that also, because it asked how it could be broken down AND how it dissolves
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    (Original post by anndz3007)
    where do you put the charge on A ?? i thought nothing break down so i just leave it neutral ??
    It's called "Molecular ion peak" and i remembered my teacher banging on about + charge so I just put the whole molecule and that whole thing has + charge
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    For the difference between chemical synthesis and fermentation of sugars I think I wrote that fermentation of sugars uses renewable resources or something like that.
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    (Original post by FluffyCommie)
    It was two doublets and one Sextet (a multiplet would have sufficed)
    I thought one of the H's was adjecent to a carbon with no H's so producing a singlet.
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    Okay paper
    Don't wanna get too confident
    Probably lost some marks on those explanation three markers
    Hopefully the examiners can read my structures
    Bricking it for F325 now
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    (Original post by cr7alwayz)
    For the first step of the incomplete mechanism question (2 marks),

    I just put positive dipole on the carbon and negative dipole on the oxygen.
    And a curly arrow going from the double bond to the oxygen.

    Did we have to draw the OH- attacking the carbon with a curly arrow as well?
    I think so :/
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    (Original post by mattyk5)
    I mentioned that also, because it asked how it could be broken down AND how it dissolves
    They're stitches though, so don't think they'd be exposed to that enough for it to work


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    (Original post by ShannonD_1697)
    What do people think the boundaries will be for a grade C?
    Also can anyone explain how they worked out the percentage yield question?
    -Work out the number of mols of the reagent, using the mass and the Mr (given to you in the question)
    -This gives you the theoretical amount of mols of A produced.
    -The acutal yield is 61%, so you do (61/100)*number of mols from the first part
    -This gives you the number of mols of A formed
    -using M= n*Mr you can calculate the mass of A, providing you can figure out the Mr of A from its structure

    Hope this helps
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    (Original post by ewjfksd)
    My diester was a cyclic compound do you think that would be acceptable
    the question asks you to draw a cyclic diester
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    Can the structure be CH3CH(CH3)CH(OH)CH3
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    (Original post by Timon512)
    It is definitely saturated. The question said NATURALLY occurring fatty acids and the majority of naturally occurring ones are Cis, only becoming Trans when undergoing Dehydrogenation. Plus, there was no way to tell whether Oleic or Linoleum acid were Cis or Trans but Saturated fats definitely increase your L Cholesterol levels.
    That's the thing! Even if you choose unsaturated, there's no way of knowing if it's trans or cis.....

    Hopefully it said the naturally part cos I guessed saturated!!
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    how many peaks did the carbon nmr have, during the exam i didn't look at the question properly and said only 3 peaks so i said compound F was ch3ch2ch(oh)ch2ch3, how many marks would i lose out of 7.
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    (Original post by cr7alwayz)
    For the difference between chemical synthesis and fermentation of sugars I think I wrote that fermentation of sugars uses renewable resources or something like that.
    it's about the difference of stereoiosmers formed
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    (Original post by adetutu)
    For the polyamide question, was it a use of NYLON specifically or any polyamide?
    I put Nylon and use in fabric, not sure though
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    (Original post by SlippyDuck117)
    Did anyone else fine that exam rather difficult? I would've much preferred a paper like last year's ...

    Very few standard questions and no big nmr question too

    Been getting 50-55/60 on past papers, I don't think I've got more that 40 looking back at all the mistakes I've made.
    I found 2015 very decent. This was horrible for me :c
    Had to cry my pain out. Bye bye to an A
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    (Original post by ewjfksd)
    My diester was a cyclic compound do you think that would be acceptable
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    this is what i did, it matched to formula so i think it's right
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    (Original post by drandy76)
    They're stitches though, so don't think they'd be exposed to that enough for it to work


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    Stitches arent exposed to light? they're visible so must be....
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    Would 56/60 be an A*


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