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OCR AS - Chemistry Unit F322 - Chains, energy and resource - REVISION! watch

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    (Original post by ChessMister)
    Other products produced, slow rate, high activation energy, is what I put, as it didn't specify that it wanted only one answer, which they usually do with, "Give one reason why etc..."
    Same! I put 2 answers because I saw it didn't specify one reason - I put other products produced and too high activation energy, as I'd just done a past paper with those as the answers an hour before. Needless to say I was happy at the sight of the question! :five:
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    (Original post by hatnan)
    ethyl propanoate
    I got ehtyl propanoate too
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    (Original post by viksta1000)
    +33

    You had to divide by 2 to per enthalpy change per mole
    I put 0

    Thought it said the enthalpy change of formation, and there were only elements there, and I got confused haha
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    (Original post by Robpattinsonxxx)
    For the last part will there be marks for the fragment ions that I found? even though i got the propanoic acid wrong
    Possibly, but it's doubtful. It wasn't really helpful in identifying the compound, since you had the m/z peak anyway.
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    (Original post by Awesomesauce)
    Samesies! Boom!
    Also, around -1270 can't remember exact. Ethyl Propanoate. Methylated spirits (probably wrong).

    THe only question I was really unsure about was the 'how is IR spec used to analyse NOx in the atomosphere and other pollutants ect'?/
    I put different bonds absorb IR of different frequencies so you could compare the spectra to see how much N-O bonds are present or something like that
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    i thought atom economy is more important because the process is more sustainable because i came across a question just like that in a past paper...all in all, i think its a good paper for a person to retake
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    (Original post by viksta1000)
    +33

    You had to divide by 2 to per enthalpy change per mole
    I nearly got caught out there, thank god I re-iterated the definition of enthalpy change of formation in my head to realise it was one mole of a substance is formed.
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    (Original post by lolo-x)
    I put different bonds absorb IR of different frequencies so you could compare the spectra to see how much N-O bonds are present or something like that
    I wrote take a sample of air and pass it through an IR spectrometer and see how big the N-O peak is. Total guess haha
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    (Original post by racheatworld)
    Same! I put 2 answers because I saw it didn't specify one reason - I put other products produced and too high activation energy, as I'd just done a past paper with those as the answers an hour before. Needless to say I was happy at the sight of the question! :five:
    In past papers that my teacher has marked i got the mark for just saying that the reaction does not take place directly
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    (Original post by Joseppea)
    I put that other compounds might've been formed by the reactants. :dontknow:
    you're right cos you won't just get one product, you'll end up with several products
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    (Original post by racheatworld)
    I nearly got caught out there, thank god I re-iterated the definition of enthalpy change of formation in my head to realise it was one mole of a substance is formed.
    I don't think I even thought of moles, I took a stab on another thought and got it correct!
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    (Original post by racheatworld)
    I nearly got caught out there, thank god I re-iterated the definition of enthalpy change of formation in my head to realise it was one mole of a substance is formed.
    What question was that?
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    (Original post by DeanFoley)
    I don't think I even thought of moles, I took a stab on another thought and got it correct!
    but the question didn't specifically say standard enthalpy change of formation, it just enthalpy change of formation
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    Yesss LOL i got ethyl propanoate too guys
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    Was it D and E that were the stereoisomers?
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    Is anyone else pissed at how they learnt electrophillic addition and radical substitution but only got the chance to show off their nucleophillic substitution knowledge!?
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    (Original post by SmithytheDrummer)
    Was it D and E that were the stereoisomers?
    That's what I put so hopefully!
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    (Original post by Yarpie)
    I don't think there will be marks for naming the compounds X, Y and Z. Only for finding the structural formula. For those types of questions they usually say ignore names.
    i hope so
    i got the structure right but for some weird reason i called the ester butyl propanoate
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    (Original post by SmithytheDrummer)
    Was it D and E that were the stereoisomers?
    The E/Z isomer was G.

    Wait, what question on stereoisomers was there?!
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    (Original post by Yarpie)
    I don't think there will be marks for naming the compounds X, Y and Z. Only for finding the structural formula. For those types of questions they usually say ignore names.
    It said identify, not draw the structure though..
 
 
 
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