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OCR A2 CHEMISTRY F324 and F325- 14th and 22nd June 2016- OFFICIAL THREAD watch

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    As far as mark schemes are concerned, are heat and reflux interchangeable?

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    (Original post by jontypickles)
    As far as mark schemes are concerned, are heat and reflux interchangeable?

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    For acid/alkali hydrolosis I'd say so not good for other things though. Like Heat is needed in a Esterification reaction but I'm not sure reflux would pass, check that out.
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    (Original post by pineneedles)
    RPA?

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    Rings, Polymers and analysis (the first exam) 😀 I just can't see why there's only one environment.
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    Hi guys,
    How would you know where a repeat unit ends for hydroxyl acids, I see only one unit is drawn not showing the ester bond.
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    (Original post by ForeverDay)
    Rings, Polymers and analysis (the first exam) 😀 I just can't see why there's only one environment.
    Oh, duh. Just want to make sure it's the rifht one:
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    (Original post by jerseyalevel)
    What are the chances of us being tested on organic practical methods? I know we get tested on them via. the controlled assessments, but is it possible for them to ask us to describe the method of purifying etc?
    I think they can do, but only in limited detail - ie: how would they identify two different ketones using Brady's Reagent... so you'd produce an orange precipitate, purify the crystals and compare the melting point of the purified derivative with a known database to identify the ketones.
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    (Original post by AqsaMx)
    For reduction of ketones/carboxylic acids, if you use NaBH4, is there a colour change from orange to green as well?
    No colour change.

    (Original post by AqsaMx)
    I doubt they would..

    Anyone know for sure?
    No, there are no 'practical skills' type questions.
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    (Original post by pineneedles)
    Oh, duh. Just want to make sure it's the rifht one:
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    Yep, it's that question and the one on the very left. 😀 I would've put it as 3 separate peaks not as one multiplet so I was a bit confused.
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    (Original post by ForeverDay)
    Yep, it's that question and the one on the very left. 😀 I would've put it as 3 separate peaks not as one multiplet so I was a bit confused.
    (Original post by pineneedles)
    Oh, duh. Just want to make sure it's the rifht one:
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    Lol I mixed them up too. I thought the 2.7 was the first one.

    Just a Question. does the most left one have any splitting pattern? I couldn't figure it out. I left it at the end and filled it out and got it right but those ****ing jaggy ass lines are hard to read.
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    (Original post by ReTakingF324/5)
    Lol I mixed them up too. I thought the 2.7 was the first one.

    Just a Question. does the most left one have any splitting pattern? I couldn't figure it out. I left it at the end and filled it out and got it right but those ****ing jaggy ass lines are hard to read.
    if you ever see a 'mess' at 7ppm, it is screaming at you that it is a benzene ring.

    If You look on the chemistry data sheet there is notes at the bottom which say that the peaks due to OH and NH bonds are said to be normally singlets and are BROAD. - therefore you'd know if it was a benzene or a OH/NH.
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    (Original post by danthebox)
    if you ever see a 'mess' at 7ppm, it is screaming at you that it is a benzene ring.

    If You look on the chemistry data sheet there is notes at the bottom which say that the peaks due to OH and NH bonds are said to be normally singlets and are BROAD. - therefore you'd know if it was a benzene or a OH/NH.
    Thanks for the info. Yeah I knew it was a beneze ring 100% just the fact that I couldn't work out the splitting pattern cause I got Sextet, 5 adjacent H but that didn't make sense.
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    guys do we need to know specifically what esters produce was smells e.g benzyl ethanoate is used in perfumes and shampoos etc?


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    (Original post by danthebox)
    if you ever see a 'mess' at 7ppm, it is screaming at you that it is a benzene ring.

    If You look on the chemistry data sheet there is notes at the bottom which say that the peaks due to OH and NH bonds are said to be normally singlets and are BROAD. - therefore you'd know if it was a benzene or a OH/NH.
    if theres an carboxylic acid or aldehyde or ketone im the compound will a (CH-O) at 3.5 ppm show as well?


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    (Original post by ranz)
    if theres an carboxylic acid or aldehyde or ketone im the compound will a (CH-O) at 3.5 ppm show as well?


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    That peak will only be in esters and alcohols, and will show whether its in D2O or not!
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    (Original post by danthebox)
    That peak will only be in esters and alcohols, and will show whether its in D2O or not!
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    this compound contains one O only and its an aldehyde yet theres a peak at 3-4 ppm?


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    This specification point 'Describe and explain the increased use of esters of fatty acids as biodiesel'

    What does it want us to know?
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    The markscheme for the F324 June 2015 paper, says (hot) ethanol ammonia for question 3aiii. But I put ethanolic ammonia, warm and my teacher has marked it right. Do you think this is okay, or should I stick with hot ethanolic ammonia???
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    (Original post by AqsaMx)
    This specification point 'Describe and explain the increased use of esters of fatty acids as biodiesel'

    What does it want us to know?
    i guess thats in renewable and good alternative source to fossil fuels, and its easily produced using waste cooking oil or crops


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    (Original post by tcameron)
    f324 2015:
    Thank you!
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    (Original post by LeesaN28)
    The markscheme for the F324 June 2015 paper, says (hot) ethanol ammonia for question 3aiii. But I put ethanolic ammonia, warm and my teacher has marked it right. Do you think this is okay, or should I stick with hot ethanolic ammonia???
    when its in brackets (hot) then its not needed for the mark, but id write from now on hot. i think warm and hot they mean the same thing right?


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