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    (Original post by irishwannabevet)
    i wrote distorted linear - don;t suppose that will merit a mark...was rushing and couldn't think..
    hmm distorted linear? well in the book it said 'non linear' and even in the mark schemes of previous years. i suppose distorted linear is basicly non linear
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    (Original post by Sahds)
    oooh about the detection 1, i wrote that the no. of electrons released when ions hit the detector is parallel to m/z ratio.. is that alrite?

    other people wrote it was simply that a current was produced at the detector

    itll be a shame if i mess this up.. i love chemistry and revised thoroughly for it
    I wrote both as I couldn't be quite sure what they were asking for.

    So can no one remember what they got for the ideal gas equation question?
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    (Original post by theultimate)
    lol proportional not parallel
    aah.. is it wrong then??
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    Well now I want to talk about the m/z question.
    I labeled the x-axis m/z value
    y-axis something intensity

    Next I didn't get this but then looked closer:
    75% of the 35C isotope and
    25% of the 37C isotope

    35+ has m/z 35 Shown as 6 units originally
    35(2+) has m/z 17.5 Drew up to 6 units
    37+ has m/z 37 Drew up to 2 units
    37(2+) has m/z 18.5 Drew up to 2 units

    It's not exactly accurate as I can't remember it all but this is what I did.
    So Isotope 35 has 12 12/16= 75%
    Isotope 37 has 4 4/16=25%
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    Considering the very dodgy questions they asked in this paper, i reckon the boundry this year will be 45/60 or even possibly less for an A. Jan 07 paper was much easier than this and an A was 47/60.

    Too late now, i need to concentrate on tomorrow's physics. And i can always retake this in June lol.
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    (Original post by dancingbeth)
    I wrote both as I couldn't be quite sure what they were asking for.

    So can no one remember what they got for the ideal gas equation question?

    about 1.90dm3

    or 0.00190m3
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    ooh i got sum crazy answer.. 7m3 but luckily i checked through it and realised its wrong. the answer i got when i re did it was something like 1..... x10(-4/-3)m3 if my memory is like it was
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    What do people think it will be for maximum UMS?
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    (Original post by theultimate)
    about 1.90dm3

    or 0.00190m3
    Got the same answer.
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    (Original post by theultimate)
    about 1.90dm3

    or 0.00190m3
    Yes me too
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    Come on guys lets move this topic on

    (Original post by Lamba)
    Well now I want to talk about the m/z question.
    I labeled the x-axis m/z value
    y-axis something intensity

    Next I didn't get this but then looked closer:
    75% of the 35C isotope and
    25% of the 37C isotope

    35+ has m/z 35 Shown as 6 units originally
    35(2+) has m/z 17.5 Drew up to 6 units
    37+ has m/z 37 Drew up to 2 units
    37(2+) has m/z 18.5 Drew up to 2 units

    It's not exactly accurate as I can't remember it all but this is what I did.
    So Isotope 35 has 12 12/16= 75%
    Isotope 37 has 4 4/16=25%
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    Id be surprised if anyone did well enough to get maximum UMS.
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    good
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    I did:

    6 units for 35
    1.5 units for 35-2+
    2 units for 27
    .5 units for 37 - 2+

    ( each unit represented 10 % in my mind)
    Think the important things were to have the 2+ peaks significantly smaller than the + peaks and to represent the percentages accurately
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    NH4 + regular tetrahedral - explain?

    that was like 4 marks wasnt it?
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    (Original post by Lamba)
    Well now I want to talk about the m/z question.
    I labeled the x-axis m/z value
    y-axis something intensity

    Next I didn't get this but then looked closer:
    75% of the 35C isotope and
    25% of the 37C isotope

    35+ has m/z 35 Shown as 6 units originally
    35(2+) has m/z 17.5 Drew up to 6 units
    37+ has m/z 37 Drew up to 2 units
    37(2+) has m/z 18.5 Drew up to 2 units

    It's not exactly accurate as I can't remember it all but this is what I did.
    So Isotope 35 has 12 12/16= 75%
    Isotope 37 has 4 4/16=25%

    see, thats exactly wat i did, so there were a pair of identical lines at the 17.5 end and the 37 end.
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    (Original post by TU123)
    Id be surprised if anyone did well enough to get maximum UMS.

    not really
    UMS changes due to how hard the paper is so it is fairly constant every time

    it would be suprising if anyone got full marks!

    full ums is this tricky paper may be about 57/60
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    (Original post by TU123)
    Id be surprised if anyone did well enough to get maximum UMS.
    They scale it so there will always be roughly the same amount of people who get maximum UMS.
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    I got 1.90x10-3m3...

    What was the answer to the very last question. I put S8 is heavier that Cl2 so the force are stronger but surly that isnt worth 5 marks?
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    8 outer electrons = 4 bonding pairs and no lone pairs = tetrahedral
 
 
 

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