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OCR A Chemistry Paper 2 Unofficial Mark scheme Watch

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    71% yield.
    Did anyone get 95 repeat units?
    Ester for hydrogen NMR. This includes 3 CH3.
    At the end L was a Ester: CH3CH2COOCH2C(CH3)2CH3
    M was a carboxylic acid: CH3CH2COOH
    N was an alcohol : HOCH2C(CH3)2CH3 (Ashleigh)
    recrystallisation for the method.
    Phenol with ethanone joined together. for C NMR.
    https://www.thestudentroom.co.uk/att...2&d=1497870262
    Butan-1-ol + 2O] --> Butanoic acid and Water, using acidified potassium dichromate and under reflux
    Butan-1-ol + [O] --> Butanal and water, using acidified potassium dichromate and distillation technique (AnnaRainbows)
    Diol more soluble as it has two hydroxyl groups.
    Alcohol forms h bonds with water so soluble.
    https://www.google.co.uk/url?sa=i&rc...97957876618458
    Beta carotene Q
    C40H56 + 11H2 --> C40H78 (TuffyandTab)

    MCQ
    BDCBDCACCBCAACB (tamoni4)
    AgNo3
    C7H14 - molecular formula
    Addition reaction (economy)
    Trigonal planar - Atom no. 3
    3 peaks for NMR in MCQ
    3 or 4 Chiral carbons??
    Acyl chloride + primary amine = amide MCQ
    Alicyclic and saturated??

    Good Paper!!!
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    (Original post by Boss987)
    71% yield.
    Did anyone get 95 repeat units?
    Ester for hydrogen NMR. This includes 3 CH3.
    recrystallisation for the method.
    Ketone with benzene for C NMR.

    MCQ
    3 peaks for NMR in MCQ
    3 Chiral carbons??
    Acyl chloride + primary amine = amide MCQ

    Help me finish the mark scheme!!!
    1st question AgNO3, another multiple choice is C6H14 maybe it was c7
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    (Original post by Boss987)
    71% yield.
    Did anyone get 95 repeat units?
    Ester for hydrogen NMR. This includes 3 CH3.
    recrystallisation for the method.
    Ketone and phenol group with benzene for C NMR.
    https://www.thestudentroom.co.uk/att...2&d=1497870262

    MCQ
    3 peaks for NMR in MCQ
    3 Chiral carbons??
    Acyl chloride + primary amine = amide MCQ

    Help me finish the mark scheme!!!
    i got 4 chiral centres but im **** so im probably wrong

    other questions i vaguely remember

    butan-1-ol
    the oxidation well it was distil to aldehye and reflux to COOH wasn't it? both with K2Cr2O7/H+



    that recrystallisation was purity of benzoic acid after substituted with no2 + % yield



    MCQS:
    some bond angle ****
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    (Original post by Boss987)
    71% yield.
    Did anyone get 95 repeat units?
    Ester for hydrogen NMR. This includes 3 CH3.
    recrystallisation for the method.
    Ketone and phenol group with benzene for C NMR.
    https://www.thestudentroom.co.uk/att...2&d=1497870262

    MCQ
    3 peaks for NMR in MCQ
    3 Chiral carbons??
    Acyl chloride + primary amine = amide MCQ

    Help me finish the mark scheme!!!
    I got a ketone and phenol?
    And 4 chiral centres
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    My MCQ answers were: BDCBDCACCBCAACB
    Formula of unsaturated beta carotine was C40H56
    Nylon 6,6 had 95 repeat units
    For the first NMR question I had a phenylketone (C8H8O2)
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    Pray for error carried forward D: I definitely didn't get the right compound for the last NMR question my dumbass put amino acid rip
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    How many marks will I lose for putting h+ in the oxidation equation instead of H2O? (I put H2O and then crossed it out)
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    Hmmm for repeat units i got 140
    C40H22
    Phenol Ketone
    Bond angle atom C
    Branching - less points of surface contact hence weaker London forces
    Yield = 73.56% (something along those lines)
    Combined techniques last question was an ester

    4 Chiral carbons
    3 peaks for MCQ
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    Last question I got an ester - CH3CH2COOCH2C(CH3)3
    Question before with carbon-13 NMR - phenol with ethanone joined together.

    I'm pretty certain on these.
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    Beta carotene Q
    C40H56 + 11H2 --> C40H78
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    (Original post by Boss987)
    71% yield.
    Did anyone get 95 repeat units?
    Ester for hydrogen NMR. This includes 3 CH3.
    recrystallisation for the method.
    Ketone and phenol group with benzene for C NMR.
    https://www.thestudentroom.co.uk/att...2&d=1497870262
    Butan-1-ol + 2O] --> Butanoic acid and Water, using acidified potassium dichromate and under reflux
    Butan-1-ol + [O] --> Butanal and water, using acidified potassium dichromate and distillation technique (AnnaRainbows)
    Diol more soluble as it has two hydroxyl groups.
    Alcohol forms h bonds with water so soluble.
    https://www.google.co.uk/url?sa=i&rc...97957876618458

    MCQ
    BDCBDCACCBCAACB (tamoni4)
    AgNo3
    C7H14 - molecular formula
    Addition reaction (economy)
    Trigonal planar - Atom no. 3
    3 peaks for NMR in MCQ
    3 Chiral carbons??
    Acyl chloride + primary amine = amide MCQ

    Help me finish the mark scheme!!!
    yep got 95 repeat units mr was something like 226 if you remember . what did yoou get for the beta carotene question, that was one i was unsure of
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    (Original post by Tuffyandtab)
    Last question I got an ester - CH3CH2COOCH2C(CH3)3
    Question before with carbon-13 NMR - phenol with ethanone joined together.

    I'm pretty certain on these.
    I agree!
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    (Original post by blazingriver)
    1st question AgNO3, another multiple choice is C6H14 maybe it was c7
    it was c7h14 which was choice C i think
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    For the last NMR question, I've got a
    2,2-dimethylpropyl ethanoate
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    In the beta carotene question it said it had 2 rings, was that referring to benzene rings?
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    (Original post by mobrien2404)
    In the beta carotene question it said it had 2 rings, was that referring to benzene rings?
    No, they would have said aromatic rings if it was benzene.
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    Why is it AgNO3 to measure the rate of activity/reaction? I put KCl because to see which one reacts fastest you need a displacement reaction? Cl displaces both iodine and bromine and then you can look at the speed... oh gosh
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    (Original post by Tuffyandtab)
    Last question I got an ester - CH3CH2COOCH2C(CH3)3
    Question before with carbon-13 NMR - phenol with ethanone joined together.

    I'm pretty certain on these.
    but there was no C-O bond in the CNMR diagram, so how could it be phenol??
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    (Original post by mobrien2404)
    In the beta carotene question it said it had 2 rings, was that referring to benzene rings?
    Nope it could have also meant alicyclic rings not aromatic
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    (Original post by AnnaRainbows)
    Why is it AgNO3 to measure the rate of activity/reaction? I put KCl because to see which one reacts fastest you need a displacement reaction? Cl displaces both iodine and bromine and then you can look at the speed... oh gosh
    To see which one forms the precipitate first. Ag+(aq) + X-(aq) -------> AgX(s)
 
 
 
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