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OCR Chemistry A Exam Thread (Breadth - May 27 2016 and Depth - June 10 2016) Watch

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    (Original post by 87Mack)
    nah it was 6H20
    I got 6 too.


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    Lol had to wait 20 minutes for invigilators to find data sheets
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    (Original post by therealbatman365)
    I got Br2 to make a dibromo haloalkane and then NaOH(aq) to make the diol???
    yeahhh boiii i got the same
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    Ohh lorraine
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    (Original post by Harryg123456)
    3.3 i got
    Also got that
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    (Original post by 2kk2)
    for the last question were you meant to add Hbr to the alkene so you get a haloalkane which formed the secondary alcohol - what were the regeants and how many marks would you lsoe if you missed out the regeants
    Pretty that the reagent for turning the the alkene into the blank product (C4H8Br2) was Br2. Then, to turn that into a diol, you could use NaOH.
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    (Original post by Harryg123456)
    3.3 i got
    yes mate
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    (Original post by Clintbarton)
    It would be halogenation - just Br2 because you can't create -OH from the the H-C formed in nucleophilic addition. The reagents were Br2 and H2O as steam for the second part?


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    H2O I believe is a weak nucleophile so normally reagents like NaOH are used BUT I don't think you'll lose a mark
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    (Original post by SGHD26716)
    I used 100 as they mixed the two solutions together
    I did this too

    (Original post by A Sajid)
    100% sure it was CrCl3.8H20
    If you assume the salt was only CrCl3 (no hydrogen or oxygen) then you should get 6H2O, if you've done the empirical formula correctly
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    What did people get when it asked for the equilibrium concentration of SO3 in the question asking about yield, I got something like square root of 30 after rearranging the equation and simplified, but I'm pretty sure that's wrong?
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    did anybody get 0.768 for conc of so3?
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    What did y'all put for q15 about the non-polar e/z isomers on MCQ?
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    What was the % error? My answer was something like 1.7%. And I've said that to decrease the error you have to add a bigger mass of hydrated salt so that more water would be lost which will decrease the (error / mass) fraction.
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    (Original post by ukgjyhtrhv)
    best chemistry exam ive hever done 😃😃 absolutely buzzing but i think grade boundaries will be high around 90%
    oi are you serious i flopped that so bad
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    (Original post by A Sajid)
    No. For that question they gave conc and vol. So you can work out the moles from that. And then using the moles, you can work out mass by doing moles x mr. That would given you the mass in g which is what you need to do q=mct
    They said to assume the mass of the solutions was the same as water
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    (Original post by Jitesh)
    H2O I believe is a weak nucleophile so normally reagents like NaOH are used BUT I don't think you'll lose a mark
    Ah yes but I seem to recall them saying something about the fastest route of synthesis? Oh well.
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    (Original post by 87Mack)
    did anybody get 0.768 for conc of so3?
    Yeh I got something like that
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    Name:  C.png
Views: 270
Size:  254.3 KBAttachment 539401539403
    Similar to one of the questions but I used 100cm3 as the student added an extra 50cm3 of something
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    (Original post by therealbatman365)
    What did y'all put for q15 about the non-polar e/z isomers on MCQ?
    i put B
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    (Original post by 87Mack)
    nah it was 6H20
    So pissed with myself. I clearly didnt read the question. I wrote CrCl3H12O6 and didnt realise is was water of crystalisation
 
 
 
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