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Chemistry unit 4 AQA

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    What topics are most likely to come up on this exam?
    Whats not on the past papers?

    This was posted from The Student Room's Android App on my GT-S5830
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    has chromatog ever come up?
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    Chromatography has come up once, I remember a 4-6 mark question on chromatography in section B on one of the past papers. They also linked it in once on a question to do with the separation of amino acids after a dipeptide had been hydrolysed, only one mark though.
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    (Original post by StraightUpG)
    has chromatog ever come up?
    Only once!


    (Original post by kontemptXD)
    Chromatography has come up once, I remember a 4-6 mark question on chromatography in section B on one of the past papers. They also linked it in once on a question to do with the separation of amino acids after a dipeptide had been hydrolysed, only one mark though.
    Don't think it was 6! More towards 3 I think i'll have a look tomorrow
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    (Original post by Doctor.)
    Only once!



    Don't think it was 6! More towards 3 I think i'll have a look tomorrow
    hmm got a feeling something like that will come up this time.. think boundries will be lower than or similar to jan 12
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    (Original post by StraightUpG)
    hmm got a feeling something like that will come up this time.. think boundries will be lower than or similar to jan 12
    I agree, think the grade boundaries will be similar to Jan'12
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    http://store.aqa.org.uk/qual/gce/pdf...W-QP-JUN10.PDF

    can someone help me with Q4 b how can you tell how many molecular ion peaks there are going to be :/
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    (Original post by swert)
    http://store.aqa.org.uk/qual/gce/pdf...W-QP-JUN10.PDF

    can someone help me with Q4 b how can you tell how many molecular ion peaks there are going to be :/
    There are 4 chlorine atoms in that molecule therefore the possible combinations of chlorine atoms will be;
    Cl-37 Cl-37 Cl-37 Cl-37
    Cl-37 Cl-37 Cl-37 Cl-35
    Cl-37 Cl-37 Cl-35 Cl-35
    Cl-37 Cl-35 Cl-35 Cl-35
    Cl-35 Cl-35 Cl-35 Cl-35
    Therefore there will be 5 molecular peaks.
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    hi, in the spec it says 'be able to perform calculations for the titrations of
    monoprotic and diprotic acids with sodium hydroxide, based
    on experimental results' im stuck on this so can anyone offer any help!?

    e.g In a titration we find that the equivalence point is reached when 25cm3 of 0.0150 mol dm-3 NaOH is neutralised by 15.0cm3 HCL. what is the conc of the acid?

    and what else do we need to know for titrations? Thanks
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    Can anyone link me a paper with all correct answers and working for January 2012? Can't learn anything from a mark scheme... would be greatly appreciated.

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Updated: January 10, 2013
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