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Edexcel paper 2 chem unofficial mark scheme Watch

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    (Original post by Yusuf121)
    For the activation energy question I got around -7000 as my gradient and therefore got +53.97kj for my activation energy. I also got 10.11g for the mass of nitrogen using the pv=nRT. A lot of my friends got similar answers!
    The general consensus here seems to be near 84 for Ea and 21.97 for nitrogen gas
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    (Original post by Yusuf121)
    For the activation energy question I got around -7000 as my gradient and therefore got +53.97kj for my activation energy. I also got 10.11g for the mass of nitrogen using the pv=nRT. A lot of my friends got similar answers!
    I got +84.5 (something like that)
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    (Original post by glad-he-ate-her)
    Organic synthesis- conc no3, conc h2so4 goes to nitrobenzene then add tin and conc hcl to phenylamine then add ethanoyl chloride ( with no halogen carrier) to desired product
    Ea was 84000 nearabouts joules, and divide for kj
    mass of nitrogen was 21.97
    Orders were x-1 y-2 z-0 k was 241.11
    Diff proton nmr, one had 5 one had 4 intensity was like 3 to 2 to 2 to 1 and 1 to 2 to 2 to 2 to 1
    find chemical shifts from data booklet and state splitting patterns
    24 DNPH derivates, orange crystalline forms, recrystallise ppt, find mp using capillary tube method- compare with database of known bradys reagent derivatives
    catalyst was adsrorbption, bond weakening then desrorption- explain those terms
    graphie and graphene was single layer of hexagons, bond angle 120 and poor electrical conductivity was answer
    reforming equation was just make cyclic and balance with hydrogen
    2NO+2CO---2co2 +N2 was an answer
    conc of bromine was 0.255
    paracetomal percent was 93.6
    Haha unlike last time, I'm in full agreement with all of these mate! Although the graphite/graphene ones took a bit of thinking outside the box
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    (Original post by Florent venhari)
    I got +84.5 (something like that)

    Same. They usually give a range for finding the activation energy questions, you will 100% get the marks if your value was between about +82 to +87 kJ per mole
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    I think if you get a ton of nitrogen as your answer to a question asking how much are in car tyres, you may need to think about it that's realistic lol
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    (Original post by mohsam)
    Haha unlike last time, I'm in full agreement with all of these mate! Although the graphite/graphene ones took a bit of thinking outside the box
    Yeah that was a little cheeky, wording threw me off initially
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    (Original post by mohsam)
    I think if you get a ton of nitrogen as your answer to a question asking how much are in car tyres, you may need to think about it that's realistic lol
    Nah havent you heard about the billions of tonnes of extra nitrogen we pump into our car tyres every year, lucrative business that
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    (Original post by Florent venhari)
    Went over the paper with my teacher! This mark scheme is looking good too! Ngl, but think I got FULL marks! Hope paper 3 is as easy. 🙌
    Do hydrogens in benzene have just one chemical environment in proton nmr? How many chemical environments were there for phenylethanone and phenylethanal?
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    (Original post by glad-he-ate-her)
    Organic synthesis- conc no3, conc h2so4 goes to nitrobenzene then add tin and conc hcl
    You see I have a slight problem with that, when you reduce nitrobenzene you actually get a protonated phenylamine instead of a normal phenylamine therefore you have to reflux it with naoh. The problem was they didnt give naoh as a reagent...did anyone else get stumped by this?

    Or i may be overthinking this...its been a long day
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    (Original post by glad-he-ate-her)
    Oh yeah i dont even think i put it thinking back.
    Pretty certain on 84000, few of my friends got the same
    It said write it in kJ/mol therefore it would be 84 surely
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    (Original post by AmyBalint)
    It said write it in kJ/mol therefore it would be 84 surely
    Yeah your answer should be between +82 and +87, make sure you had the sign. It wanted the gradient value, which if I remember correctly was like -10,000?
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    (Original post by AmyBalint)
    It said write it in kJ/mol therefore it would be 84 surely
    think he meant in j per mol which then needed to become kj per mol
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    (Original post by AMA7777)
    think he meant in j per mol which then needed to become kj per mol
    Average of 75% on track for an A???
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    Think I did pretty well, I left the synthesis route question because I didn't even know how to do that.
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    (Original post by xxVENUSx)
    Think I did pretty well, I left the synthesis route question because I didn't even know how to do that.
    Form in to nitrobenzene, then reduce to phenylamine, then react with ethanoyl chloride. Simples!
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    What did you all write for the proton NMR of phenylethanone and phenylethanal?
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    for the organic symthesis, for my last step i used ethanoic acid instead of ethanoyl chloride to get a leaving group of water. dyou think thats ok?
    (Original post by glad-he-ate-her)
    Organic synthesis- conc no3, conc h2so4 goes to nitrobenzene then add tin and conc hcl to phenylamine then add ethanoyl chloride ( with no halogen carrier) to desired product
    Ea was 84000 nearabouts joules, and divide for kj
    mass of nitrogen was 21.97
    Orders were x-1 y-2 z-0 k was 241.11
    Diff proton nmr, one had 5 one had 4 intensity was like 3 to 2 to 2 to 1 and 1 to 2 to 2 to 2 to 1
    find chemical shifts from data booklet and state splitting patterns
    24 DNPH derivates, orange crystalline forms, recrystallise ppt, find mp using capillary tube method- compare with database of known bradys reagent derivatives
    catalyst was adsrorbption, bond weakening then desrorption- explain those terms
    graphie and graphene was single layer of hexagons, bond angle 120 and poor electrical conductivity was answer
    reforming equation was just make cyclic and balance with hydrogen
    2NO+2CO---2co2 +N2 was an answer
    conc of bromine was 0.255
    paracetomal percent was 93.6
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    (Original post by mailboxhotbox)
    for the organic symthesis, for my last step i used ethanoic acid instead of ethanoyl chloride to get a leaving group of water. dyou think thats ok?
    Its fine chemistry wise
    practically- lower yield and less efficient
    but you will get full marks provided rest was ok
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    For the question asking about the conversion of the ketone into the alcohol...i thought it was a primary alcohol for some reason and so instead of just using LiAlH4 in dry ether as a reducing agent, I said to add I2 and NaOH to the ketone product which would form a carboxylic acid and then reduce that using LiAlH4. Would that still get me the marks?
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    I love you. best of luck for you're next exams brother
    (Original post by glad-he-ate-her)
    Its fine chemistry wise
    practically- lower yield and less efficient
    but you will get full marks provided rest was ok
 
 
 
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