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    (Original post by EternalDoom)
    I thought i did it wrong at that stage, but u had to times the empirical formula by 2 to get the molecular formula
    I think I tried that but it didn't work so I just said it didn't agree with the empirical formula :L
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    (Original post by Midgeamoo)
    What a ridiculous paper for a chemistry exam.
    Why bother revising half the theoretical (interesting) stuff when they're going to throw a bunch of essay style questions about sustainability and the environment, which was a tiny part of the syllabus.
    I really need an A in this paper, and don't know if I got it because I know i messed up the radical question (didn't know NO2 was a radical) and missed a 1 or 2 marks on the last question (had a silly moment and did the empirical formula for X wrong - still got it right overall though)
    It now just depends on if they deem my paragraphs on sustainability and "international co-operation" correct (hardly shows skill at chemistry).
    [/rant]

    I'm pretty annoyed at OCR, first the wrong question in the D1 exam yesterday, now a really pathetic chemistry paper. I guess I'll feel better about it soon.
    NO is the radical
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    (Original post by kimmey)
    for the one where you had to draw the stuff out of the cyclic compound

    first when u add H2 did u jus draw the same thing without a double bond ?

    and then for the other ones when u add HBr did u just draw it out but add a bromine and then for the second product did u jus move the position of the bromine ?????????
    Exactly right, I believe. (Well its what I put and its what made logical sense)

    So for the first one with hydrogen, you just removed the double bond and put 1 extra Hydrogen on each of the carbons that were in the double bond. Then for the HBr, the first one you would've put the H on the first carbon in the double bond, and the Br on the second, then for the second product from HBr, the Br on the first carbon that was in the double bond, and the H on the second.
    (Sorry if I've explained it rubbish)
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    (Original post by rennythetoad16)
    Didnt really like this paper
    Do you by any chance enjoy chemistry and not enjoy talking about global warming and environmental agreements? xP
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    (Original post by Midgeamoo)
    Do you by any chance enjoy chemistry and not enjoy talking about global warming and environmental agreements? xP
    This.
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    Did anyone else notice that on the last the question the melecular ion for Y was at 47, but there are no alcahols that can be formed with 47m/z. :confused:
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    i thought the paper was bladdy hard :/ , anyone started making a mark scheme yet?
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    (Original post by newreaper19)
    Did anyone else notice that on the last the question the melecular ion for Y was at 47, but there are no alcahols that can be formed with 47m/z. :confused:
    That it is plus 1 peak; it says in the book to ignore it
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    (Original post by newreaper19)
    Did anyone else notice that on the last the question the melecular ion for Y was at 47, but there are no alcahols that can be formed with 47m/z. :confused:
    I think you're meant to discount the really small peaks at the end and go for the biggest (the small ones are like isotopes of the alcohol, or something like that)
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    when i finished i thought it wasnt that bad. BUT...now i am realising how many mistakes i made...OOPS...
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    (Original post by racheatworld)
    Exactly right, I believe. (Well its what I put and its what made logical sense)

    So for the first one with hydrogen, you just removed the double bond and put 1 extra Hydrogen on each of the carbons that were in the double bond. Then for the HBr, the first one you would've put the H on the first carbon in the double bond, and the Br on the second, then for the second product from HBr, the Br on the first carbon that was in the double bond, and the H on the second.
    (Sorry if I've explained it rubbish)
    I did this. I hope it's correct
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    Structural Isomers were D & E

    Unsaturated Hydrocarbon was F

    Last question was ethyl propanoate

    Enthalpy question was -1279
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    (Original post by newreaper19)
    Did anyone else notice that on the last the question the melecular ion for Y was at 47, but there are no alcahols that can be formed with 47m/z. :confused:
    No, the molecular ion peak was at 46, there was a tiny peak at 47 due to the presence of a carbon-13 isotope, but it was too small to be the molecular ion peak.
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    (Original post by newreaper19)
    Did anyone else notice that on the last the question the melecular ion for Y was at 47, but there are no alcahols that can be formed with 47m/z. :confused:
    it was 46 and you can make ethanol,if i get it a bit out i just write the alcholhol nearest the number
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    (Original post by Moiiu)
    Structural Isomers were D & E

    Unsaturated Hydrocarbon was F

    Last question was ethyl propanoate

    Enthalpy question was -1279
    You mean saturated hydrocarbon
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    (Original post by racheatworld)
    No, the molecular ion peak was at 46, there was a tiny peak at 47 due to the presence of a carbon-13 isotope, but it was too small to be the molecular ion peak.
    someones been reading the textbook!
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    (Original post by ChessMister)
    someones been reading the textbook!
    General concencus is you need to do this to pass exams
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    I think. I have made a horrific mistake on the last question. Why did they have to make it so complex with different information for X and Y and Z. >.<
    i think i used the m/z for X which was 74 to mean the whole thing.
    worked out empirical formula for x. C3H6O or something like that. And then assumed it to be the whole thing ie z.
    mentioned that X was a carboxylic acid.
    and y was an alcohol,
    and then i think i split what was meant to be X into X and Y, so i got a lot smaller :/ i correllated some of the m/z peaks to X and Y rather than subunits of just Y. :/
    i got methanol and ethanoic acid (im not very good at naming acids and all that anyway :/) so i got Z to be ethyl methanoate. I drew all the skeletal formulas for each section though

    OOPS.

    am i likely to get any marks out of 10?
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    Would the last question be broken down into:
    Compound X
    1 mark for using the first infrared peak
    2 marks for the empirical formula
    1 mark for the calculation of molecular formula/name

    Compound Y

    2 marks for the infrared absorption
    2 marks for recognising alcohol/name

    1 mark for Ester (ECF for if you got other parts right)?
    1 mark for QWC?
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    (Original post by nereik6794)
    General concencus is you need to do this to pass exams
    ok ok; someone has been reading the textbook (as opposed to being taught) with such intensity that they remember the numerous little hints offered by OCR
 
 
 
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