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    (Original post by DeanPauww)
    Yeah but it also asked how you would check the purity so I said do a melting point test and compare to a known value and do percentage difference
    I wrote measure the melting point range and the smaller the range the more pure the substance is.
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    (Original post by AB199)
    Also why would they ask that if M and N are implicit in your structure of L, that requires no thinking whatsoever lol
    M & N IR was just showing it was an ester, you could have done that question without even looking at M & N values, and only looking at the splitting pattern.
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    (Original post by Hello247246)
    M & N IR was just showing it was an ester, you could have done that question without even looking at M & N values, and only looking at the splitting pattern.
    Wouldn't have got 6 marks tho
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    (Original post by AB199)
    Wouldn't have got 6 marks tho
    Yh I know you only had to select certain peaks and show that it meant an alcohol group and acid. You didn't need to draw the structure of the acid and alcohol.
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    I think it was 4 chiral centres mate, but the rest looks good
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    Do you think H20 and HCL would be ok instead of aqueous HCL for hydrolysis of nitrile?
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    (Original post by tom tinker)
    Do you think H20 and HCL would be ok instead of aqueous HCL for hydrolysis of nitrile?
    That's right
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    Did we have to draw the displayed formula for HCl and H2O or are we ok putting it down in the kekule notation
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    (Original post by AB199)
    Wouldn't have got 6 marks tho
    I think you would have got 6 if you got the ester without including the structure of the other 2 compounds. Probably saying it was acid hydrolysis and showing what info you got from the IR would have got you all 6
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    (Original post by TLS1234)
    I think you would have got 6 if you got the ester without including the structure of the other 2 compounds. Probably saying it was acid hydrolysis and showing what info you got from the IR would have got you all 6
    Just a quick question I got 95.1 for the number of repeats, but rounded it up to 96? I thought it made more sense that having 0.1 of something. Is that wrong?
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    (Original post by iamDev)
    It was weakly acidic as ph 5. So it's carboxylic acid or phenol.not c acid because it didn't react with carbonate. Must be phenol
    phenol would not form an orange precipitate with 2,4 DNP as it does not have a
    c=o bond and it did not react with tollens so it must be a ketone
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    (Original post by TLS1234)
    I think it was 4 chiral centres mate, but the rest looks good
    I counted 5 chiral centres, but most people are saying 4 so maybes I'm wrong
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    (Original post by bhav1234)
    phenol would not form an orange precipitate with 2,4 DNP as it does not have a
    c=o bond and it did not react with tollens so it must be a ketone
    Its a ketone AND phenol
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    (Original post by TheAlphaParticle)
    but there was no C-O bond in the CNMR diagram, so how could it be phenol??
    can't remember the c-nmr but you could tell from the table alone it was phenol. No reaction with na2co3 means the othe functional group couldn't be a carboxylic acid and it said it had a pH of 5. The only other functional group therefore could have been phenol as it's the only once that would have not reacted with tollens or na2co3 but still given slight acidity
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    (Original post by Hello247246)
    Just a quick question I got 95.1 for the number of repeats, but rounded it up to 96? I thought it made more sense that having 0.1 of something. Is that wrong?
    I rounded down to 95, i cant remember how many marks it was but if it was 2 or more, then you would get marks for correct workings and error carried forward
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    (Original post by yasminhamilton17)
    can't remember the c-nmr but you could tell from the table alone it was phenol. No reaction with na2co3 means the othe functional group couldn't be a carboxylic acid and it said it had a pH of 5. The only other functional group therefore could have been phenol as it's the only once that would have not reacted with tollens or na2co3 but still given slight acidity
    Yh I'm pretty sure its phenol but the C-O peak was supposed to occur at 40-60 and there definitely wasn't anything there, I'm not sure if it's a mistake on the exam paper but we will see
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    (Original post by TheAlphaParticle)
    but there was no C-O bond in the CNMR diagram, so how could it be phenol??
    I would also say that a C-O-H in an aromatic ring would give a different chemical shift than what would be expected, so...
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    (Original post by PeterCrabtree)
    Exactly what I got!
    Groups the other way around
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    (Original post by PeterCrabtree)
    Exactly what I got!
    Oh sorry, i drew my ester bond the other way around, i got the same thing just flipped!!
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    For people wondering about the C13 question and why its a phenol is because it tells you its relative acidity, 5, which is below neutral and alcohols and phenols are relatively acidic, so it was essentially a judgement call on what info you already knew.
 
 
 
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