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    I honestly feel I am missing something major and therefore can't finish this question off, which I think would be essential to all NMR questions.

    Okay, I got most of the vital info but I just don't know which to choose?

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    (Original post by Lawbringer)
    I honestly feel I am missing something major and therefore can't finish this question off, which I think would be essential to all NMR questions.

    Okay, I got most of the vital info but I just don't know which to choose?

    Can you show the whole question?
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    (Original post by alow)
    Can you show the whole question?


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    (Original post by Lawbringer)
    I honestly feel I am missing something major and therefore can't finish this question off, which I think would be essential to all NMR questions.

    Okay, I got most of the vital info but I just don't know which to choose?

    Hi, I don't think you're missing anything. The spectrum must be for ester (CH3)2CHCOOCH3. Distinguishing peak is the one split into 7 at 2.7ppm. (It's HC-C=O adjacent to 6 Hs). This (multiplet) wouldn't be present in the HNMR spectrum of the other ester (the peak at 2.7ppm would be a singlet because H in HC-C=O environment is not adjacent to any protons). Try and draw the structures out. Hope this helps
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    (Original post by Lawbringer)


    The shift for the 3 identical methyl protons is pretty high, what can you deduce from that?
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    (Original post by Terrificmagenta)
    x
    There are two esters which match the splitting patterns. You also need to use the shifts.
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    (Original post by alow)
    There are two esters which match the splitting patterns. You also need to use the shifts.
    Which ones??
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    (Original post by Terrificmagenta)
    Which ones??
    (CH3)2CHCOOCH3 and CH3COOCH(CH3)2.
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    (Original post by alow)
    The shift for the 3 identical methyl protons is pretty high, what can you deduce from that?
    I have no idea what you mean? This topic is killing me. I just can't finish the questions or form the actual finished products. have you got any good resources? The OCR book is so bad at explaining this, all their questions in examples are the easiest ones ever lol /rant

    I really can't make sense of how high a chemical shift can mean something?
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    (Original post by alow)
    (CH3)2CHCOOCH3 and CH3COOCH(CH3)2.
    No, the splitting for CH3COOCH(CH3)2 will be different. There would be no multiplet at 2.7ppm. It would be a singlet
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    (Original post by Lawbringer)
    I have no idea what you mean? This topic is killing me. I just can't finish the questions or form the actual finished products. have you got any good resources? The OCR book is so bad at explaining this, all their questions in examples are the easiest ones ever lol /rant

    I really can't make sense of how high a chemical shift can mean something?
    Unless you want to know a bit more about NMR, I can't think of anything. If you do, there's some Oxford Chemistry Primers that are pretty good.

    High chemical shift means that the proton's (or whatever NMR you're doing) is highly deshielded (i.e. there's less electron density around the proton). What could be a cause of this?
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    (Original post by Terrificmagenta)
    No, the splitting for CH3COOCH(CH3)2 will be different. There would be no multiplet at 2.7ppm. It would be a singlet
    It would be a septet. There is 3J coupling between the single proton and the six protons of the two methyl groups it is next to.
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    (Original post by Lawbringer)
    I have no idea what you mean? This topic is killing me. I just can't finish the questions or form the actual finished products. have you got any good resources? The OCR book is so bad at explaining this, all their questions in examples are the easiest ones ever lol /rant

    I really can't make sense of how high a chemical shift can mean something?
    I don't think you need to know anything about the significance of a high shift for the OCR spec . Dw about it, you can still pick up majority of the marks even if you don't get the final structure! I feel like a parrot rn coz i always hear my teacher say that to my friends haha. As long as you can use the n+1 rule and figure out the environments
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    (Original post by Terrificmagenta)
    I don't think you need to know anything about the significance of a high shift for the OCR spec . Dw about it, you can still pick up majority of the marks even if you don't get the final structure! I feel like a parrot rn coz i always hear my teacher say that to my friends haha. As long as you can use the n+1 rule and figure out the environments
    Well that's just terrible advice.
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    (Original post by alow)
    It would be a septet. There is 3J coupling between the single proton and the six protons of the two methyl groups it is next to.
    There arent any adjacent protons in the environment thoughh lol
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    Draw the displayed formulas for all the esters. Look at splitting patterns
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    (Original post by Terrificmagenta)
    There arent any adjacent protons in the environment thoughh lol
    Yes there are... Look again.
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    (Original post by Serine Soul)
    Draw the displayed formulas for all the esters. Look at splitting patterns
    Yeah if you see the 1st pic, I actually did that. It's just the final marks I really can't get, and I don't wish to settle with 7/8 lol. I really want to ace it haha
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    (Original post by Lawbringer)
    Yeah if you see the 1st pic, I actually did that. It's just the final marks I really can't get, and I don't wish to settle with 7/8 lol. I really want to ace it haha
    All you need to do is decide which of the singlet and multiplet would be more deshielded in either compound.
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    (Original post by alow)
    Yes there are... Look again.
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