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OCR Chemistry F322~ 4th June 2013~ AS Chemistry Watch

  • View Poll Results: How did you find the exam
    Hard A= 72
    42
    15.22%
    It was okay A= 76
    99
    35.87%
    Easy A= 79
    75
    27.17%
    Very Easy A=82
    60
    21.74%

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    (Original post by Joew1995)
    I'm also wondering about the cracking question on the first page. C15H32 can crack to form anything really can't it? That mark scheme showed a compound with C5 and a compound with C10 but I put propane and 4 molecules of propene i think, which balanced correctly.

    Do we get the mark for putting any balanced equation or does it have to be C15H32? The question didn't state any specific products being produced.
    You could put any products as long as the C's and H's add up to C15H32 and as long as you produced an alkene and an alkane
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    (Original post by Ché.)
    Yeah...
    Roughly, that's the insight of the question.
    The concept is basically asking you to mention that it is randomly broken - no cracking programming is available; this means no one controls this process.

    It totally implies the answer.., 1/1.

    Out of context to this examination, It would be controversial dependent on the function of the products and the impact in our environment...



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    Yepp it was 1 mark,I put the C-C bonds can break anywhere coz there was a similar question in one of the past papers,saying why does cracking form a mixture of alkanes and alkenes,and that was the answer.
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    Checked the unofficial mark scheme... I think I'll have at least 75 marks as I marked only the things I was sure of and left some stuff out... Hope I have some more marks and get myself an A, that would be awesome!

    Biology and Chemistry, the 50% ones and also geology, went alright, I think at least B for both, if less than that, will be really disappointing....
    The 50% exams which are supposed to be harder went better than the 30%'s lol
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    (Original post by Joew1995)
    I'm also wondering about the cracking question on the first page. C15H32 can crack to form anything really can't it? That mark scheme showed a compound with C5 and a compound with C10 but I put propane and 4 molecules of propene i think, which balanced correctly.

    Do we get the mark for putting any balanced equation or does it have to be C15H32? The question didn't state any specific products being produced.

    Can you send me a link to the mark scheme please?
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    for radical subsition i put
    1)FREE radical substitution, is that okay with the 'free' ?
    2) homolytic fission
    3) would you get a mark for saying initiation and propagation with incorrect equations?
    seems to be the question where ive lost the most marks
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    Many people are saying it went realy well, I hope the grade boundaries don't go up!

    In January 2012 it was 76 to get a B (I think recently 79 was an A) and 83 to get an A. I hope it satays at 79 or 80... Lower if possible

    *fingers crossed*
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    (Original post by Matthewgj)
    It said essential conditions.

    You may be right, but my reasoning would be behind that fermentation cannot occur unless you have the optimum temperature and the microbe present.

    The book says that fermentation can happen anaerobically, however it isn't a necessary condition.
    I put temperature of 37 degrees celcius and yeast (zymase)?
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    (Original post by Varsh05)
    Can you send me a link to the mark scheme please?
    http://www.thestudentroom.co.uk/atta...1&d=1370370378



    UNOFFICIAL MS. There's probably 1/2 errors but yeah it seems all good.
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    (Original post by Varsh05)
    I put temperature of 37 degrees celcius and yeast (zymase)?
    Thats fine
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    (Original post by Chrisd00100)
    Many people are saying it went realy well, I hope the grade boundaries don't go up!

    In January 2012 it was 76 to get a B (I think recently 79 was an A) and 83 to get an A. I hope it satays at 79 or 80... Lower if possible

    *fingers crossed*
    That Jan12 paper was ridiculously easy though

    Don't worry it won't be higher than 80 for an A, I'm pretty certain of that.
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    in propagation i wrote initially:

    CH4 + Br* -> *CH3 + HBr
    *CH3 + IBr -> CH3I + Br*

    But then I deleted the second equation and wrote the same but it forming CH3Br and I*. As In IBr, Br is more electronegative, so it will have a negative delta... dunno if that's important or not lol... I hope they alo so...

    Then made CH3I in the termination step, *CH3 + I* -> CH3I

    (Original post by TheFootyKing19)
    That Jan12 paper was ridiculously easy though

    Don't worry it won't be higher than 80 for an A, I'm pretty certain of that.
    Hope so xD I think I might have at least 72-75... Hope it's a 80+ xD
    Good luck
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    (Original post by hassanakhtaruk)
    So by writing an incorrect thing (C-H) and a correct thing (C-C) ..it's not contradicting?
    Remember?
    In this case, it should be okay.
    They do write in the notes that contradicting statements are ignored in a one-mark question.
    I mean it is one mark, but that's not the point.
    It's still a mark, 'ey!?

    I think might need the worst random somewhere or breaks everywhere in the chain of molecule.
    Have you notice they contain the sentence starter in brackets sometimes?
    The main body isn't so if that's in context then you should be awarded the mark!

    I hope you do now...
    AWARD IT OCR!



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    What would happen if I put the correct structures (i.e. ketone and aldehyde) but incorrectly named the aldehyde as butan-1-one (stupid, I know). They didn't ask us to name them, so would the marker just ignore it?
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    (Original post by Chrisd00100)
    Checked the unofficial mark scheme... I think I'll have at least 75 marks as I marked only the things I was sure of and left some stuff out... Hope I have some more marks and get myself an A, that would be awesome!

    Biology and Chemistry, the 50% ones and also geology, went alright, I think at least B for both, if less than that, will be really disappointing....
    The 50% exams which are supposed to be harder went better than the 30%'s lol
    I have come to a (hopeful) valid conclusion that the larger the module, the more endurance you need.
    I mean, Biology?
    They had first unit material as questions so candidates round have noticed!
    If you know a variety, you're totally good!

    Good luck for your results from today!


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    (Original post by MBee)
    for radical subsition i put
    1)FREE radical substitution, is that okay with the 'free' ?
    2) homolytic fission
    3) would you get a mark for saying initiation and propagation with incorrect equations?
    seems to be the question where ive lost the most marks
    The mechanism is legitimately included with the "free" part...
    LOL.



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    (Original post by MBee)
    for radical subsition i put
    1)FREE radical substitution, is that okay with the 'free' ?
    2) homolytic fission
    3) would you get a mark for saying initiation and propagation with incorrect equations?
    seems to be the question where ive lost the most marks
    Yeah, you definitely would!
    The outcome bullet points here outlined and you met one so of course!



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    Are we sure its N for the least reactive? is there nothing about tertiary halogenoalkanes?
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    (Original post by Ché.)
    Remember?
    In this case, it should be okay.
    They do write in the notes that contradicting statements are ignored in a one-mark question.
    I mean it is one mark, but that's not the point.
    It's still a mark, 'ey!?

    I think might need the worst random somewhere or breaks everywhere in the chain of molecule.
    Have you notice they contain the sentence starter in brackets sometimes?
    The main body isn't so if that's in context then you should be awarded the mark!

    I hope you do now...
    AWARD IT OCR!



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    Aww hahha thank you so much I really appreciate it I hope so too!
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    On the equilibrium question 7C, do you think that you will loose marks if you didn't state le chatilers principle??
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    how many marks was the last question
 
 
 
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