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    (Original post by Saywhatyoumean)
    I wish I knew lol hang on let me find the question Attachment 543549
    Attachment 543551

    So when I'm drawing the spectrum, why is the CH2 singlet peak between 3.3-4.3ppm instead of ~2-3ppm?




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    What year is this paper?! :O
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    (Original post by Hunnybeebee)
    The recommended adult dose of chloral hydrate as a sedative is 250 mg, threetimes a day. Calculate the mass of trichloroethanal you would need to react with water tomake one week’s supply of chloral hydrate for an adult, assuming a 60% yield.Mr: chloral hydrate, 165.5; trichloroethanal, 147.5




    mass of trichloroethanal = g

    Anyone else getting 7.41g or?
    I got 7.77...something
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    (Original post by suibster)
    surely it's because the carbon atom attached to the 2Hs is also attached to an oxygen.Therefore the corresponding chemical shift would be 3.3-4.3,which represents the HC-O proton signal.
    Exactly, surely it would be HC-O bond, shift 3.3-4.3 and not the CH2 peak and a separate OH group? I'm so confused, I've always done it this way
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    This is what me and my friend also got for the trichloroethanal question
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    Has anyone got a list/diagram/poster of what transition metal reactions we need to know? Like all of the colours of the metal ions and the ligand exchange reactions?
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    (Original post by ReeceM1)
    Has anyone got a list/diagram/poster of what transition metal reactions we need to know? Like all of the colours of the metal ions and the ligand exchange reactions?
    Have you looked at the specification? I think it explains very clearly what is required.
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    (Original post by ReeceM1)
    Has anyone got a list/diagram/poster of what transition metal reactions we need to know? Like all of the colours of the metal ions and the ligand exchange reactions?
    Pretty sure its the last point on the specification, or atleast near the end

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    I really want to get an A in chemistry so I've done all the past papers on OCR website at least 3 times... would doing legacy papers be of any help or should I not even bother with them?! ADVICE PLEASE!!!
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    (Original post by seph_muriel)
    I really want to get an A in chemistry so I've done all the past papers on OCR website at least 3 times... would doing legacy papers be of any help or should I not even bother with them?! ADVICE PLEASE!!!
    I think as long as you've learnt all the content then doing legacy papers could help.
    And where can you find them. I want to do them aswell.:yes: Thanks


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    Plenty of old past papers here: http://pastpapers.org/chemistry-a2-papers

    Enjoy everyone
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    Could anyone explain this question? And why doesn't OH substitute the Iodine?
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    (Original post by AqsaMx)
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    Could anyone explain this question? And why doesn't OH substitute the Iodine?
    I think it's just asking for structures with the molecular formula C4H8

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    (Original post by AqsaMx)
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    Could anyone explain this question? And why doesn't OH substitute the Iodine?
    OH is acting as a base under these conditions and so alkenes are formed. The conditions for nucleophilic substitution are different.
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    Do we have to LEARN Sc3+ and Zn2+ are the only ions Sc/Zn form and therefore their respective electronic configurations prove that they are not transition elements? 6 marker came up on it a couple of years ago :s
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    (Original post by itsConnor_)
    Do we have to LEARN Sc3+ and Zn2+ are the only ions Sc/Zn form and therefore their respective electronic configurations prove that they are not transition elements? 6 marker came up on it a couple of years ago :s
    Sc and Zn have only 1 stable ion, which is the one you said. Its not bad to remember, you just have to know their ion'a d subshell has 10e (for zn) and 0e (for Sc), so theyre not partially filled meaning theyre not transition elements

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    Came across this fantastic link for old chemistry past papers. The person who made this has also kindly highlighted questions that we can skip (as they aren't relevant to our spec). Enjoy!

    http://www.chemhume.co.uk/A2CHEM/Exa...additional.htm
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    Make sure you also hit the back button in the top right corner to take you to other resources, including model answers
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    (Original post by Heisenberg___)
    Came across this fantastic link for old chemistry past papers. The person who made this has also kindly highlighted questions that we can skip (as they aren't relevant to our spec). Enjoy!

    http://www.chemhume.co.uk/A2CHEM/Exa...additional.htm
    Thanks

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    Anyone know where I can find legacy papers. Thanks

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    (Original post by ImNervous)
    Anyone know where I can find legacy papers. Thanks

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    Pastpapers.org or something like that.

    Ive been going through them and tbh theyre not THAT great help. Only gone through first 4 exams though but they dont seem as helpful for f325

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