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    (Original post by High Stakes)
    Chemistry teachers looked at it and said it's relatively easy. Should be high grade boundaries.
    Are you joking?😱
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    For the rate equation i put the same as the one they gave us i thought it had no effect
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    That wasn't too bad, just a bit unlike past papers and I was REALLY pushed for time. I finished as she said 'pens down'.

    Did anyone else get the rate expression as exactly the same in the question?

    Also, what was the reason for lidocaine hydrochloride? I said to prevent the N acting as a base by protonating it and so reduces side effects. I spent about 5 minutes looking for a chiral carbon in that compound to talk about enantiomers, but I couldn't see one!
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    Did anyone else other than me find that unbearably difficult? Definitely the hardest unit 4 paper I have done
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    (Original post by j.ethers)
    Ok so for the last question we know it has to be a primary/secondary alcohol because of the dichromate reaction, but the O-H nmr peak was a singlet, suggesting the adjacent carbon to the alcohol group is itself bonded to no hydrogens. Therefore how can it be a primary or secondary alcohol??
    H is bonded to O which is bonded to C. Alcohols are always a singlet.
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    (Original post by High Stakes)
    Chemistry teachers looked at it and said it's relatively easy. Should be high grade boundaries.
    Oh, you again

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    (Original post by jakeysimps11)
    Same mate, 99% sure its correct
    i got that too but its a tertiary alcohol so doesn't turn green when dichromate is added to it
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    For the lidocaine HCL question I said as a salt is was readily soluble, and the Lidocaine could be diluted if needs be.

    Structure for last Question I got was CH3OCH2CH2C(CH3)2OH, just put what structures each chemical shift would be - wrote that it was a 1/2 alc and there was no CC double bonds present since that was all you could pull up from what they told you.
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    (Original post by chloeabeki)
    I wrote my numerical answers on my formula sheet and took it out, these are what I got...
    pH values of 2.08, 2.32 and 2.33
    1.204 for the salt/acid ratio
    0.33 mol and 4.16 mol
    9.09x10^-3 for something (kc?)
    9.402% hydrogen
    112 for the molecular ion peak
    K=3.12x10^-5
    Completely agree.
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    (Original post by cuppycake3)
    no one laugh but could it be

    (ch3)3-c-o-ch2-ch2-o-h

    i came up with that in two mins ((((((((

    Haha I got that too, but I couldn't get the structure so I was just like 'screw this' and drew some structure which looked alright to me....
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    (Original post by haj101)
    Are you joking?😱
    Only the last question was a discriminator.
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    (Original post by Cadherin)
    That wasn't too bad, just a bit unlike past papers and I was REALLY pushed for time. I finished as she said 'pens down'.

    Did anyone else get the rate expression as exactly the same in the question?

    Also, what was the reason for lidocaine hydrochloride? I said to prevent the N acting as a base by protonating it and so reduces side effects. I spent about 5 minutes looking for a chiral carbon in that compound to talk about enantiomers, but I couldn't see one!
    wasn't too bad? Are you sure about that?
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    (Original post by Joxnna_)
    nitrogen atom b had more alkyl groups (inductve effect etc) but a had an N-H bond, making that part of the molecule more soluble therefore more likely to react... right?? urgh, worst paper ever
    I put B because of the alkyls, occasionally the mark schemes allow either if they're more interested in your reasoning.
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    What were the reagents and conditions in the organic synthesis question?
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    (Original post by Sani Ej)
    For the rate equation i put the same as the one they gave us i thought it had no effect
    I agree. The only thing affecting Kc is temperature - thus rate will only depend on the differing ratio of propanone to protons.

    Don't worry, others said they found it hard, I suspect 120 UMS will be no higher than 90.
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    For the lidocaine salt question I said it was a salt so it was a solid so it could be eaten instead of injected, don't even ask, I don't know wtf I was thinking, I just wrote anything I could think of, I actually find it quite hilarious how bad that exam went
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    What did people put for the mechanism on the second question??
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    (Original post by jakeysimps11)
    Same mate, 99% sure its correct
    I put that but its wrong, that gives you a tertiary alcohol and it doesn't form a green ppt
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    (Original post by janvi24)
    I got the same
    Yay! A mark! Now up to 4!
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    (Original post by Cadherin)
    That wasn't too bad, just a bit unlike past papers and I was REALLY pushed for time. I finished as she said 'pens down'.

    Did anyone else get the rate expression as exactly the same in the question?

    Also, what was the reason for lidocaine hydrochloride? I said to prevent the N acting as a base by protonating it and so reduces side effects. I spent about 5 minutes looking for a chiral carbon in that compound to talk about enantiomers, but I couldn't see one!
    I got the rate equation the same, but I guessed.

    The reason for lidocaine hydrochloride (and I might be wrong) is the response the person below said minus the diluted bit.

    (Original post by RME11)
    For the lidocaine HCL question I said as a salt is was readily soluble, and the Lidocaine could be diluted if needs be.

    Structure for last Question I got was CH3OCH2CH2C(CH3)2OH, just put what structures each chemical shift would be - wrote that it was a 1/2 alc and there was no CC double bonds present since that was all you could pull up from what they told you.
    I said that it was a soluble ammonium salt that can be converted back into an amine by addition of NaOH
 
 
 
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