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    (Original post by ranz)
    i guess what messed me up was realising what peak was due to HC-C-N Attachment 549111 how did u guys know it was the singlet?


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    no neighbouring protons. one of the R1/ R2 is just a CH3. it is attached to another C and double bond with N. so no H beside.
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    (Original post by M.Branson98)
    When you have a salt of an amine e.g ethylammonium chloride, where do you put the positive charge? Is it on the N or what?
    preferably N but they don't penalise on that
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    (Original post by lai812matthew)
    teacher said there is gonna be an nmr for amides or halogenoalkanes.
    Oh really? Cool. Bit random, how'd she guess that it would be about those molecules exactly? lol Thanks though!
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    (Original post by bakedbeans247)
    Oh really? Cool. Bit random, how'd she guess that it would be about those molecules exactly? lol Thanks though!
    cuz it never came up in any papers before, and the exam board will try to catch people out with things that are never examined before. another thing i thought is how to distinguish a compound with stereoisomers and a compound without it. the answer is plane polarised light. and the racemic mixture thingy. it appears at AQA every year but never in OCR even though it is in the textbook!
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    (Original post by lai812matthew)
    teacher said there is gonna be an nmr for amides or halogenoalkanes.
    how do you predict that? .....
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    (Original post by bakedbeans247)
    any F324 predictions for tomorrow guys? teachers say anything?
    I'm thinking triglycerides/fatty acids in some form. Hasn't come up in 3 years

    trans fats increase low density lipoproteins/'bad cholesterol' and lead to coronary heart disease / strokes
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    (Original post by itsConnor_)
    how do you predict that? .....
    teacher not me lol, he said it never appears in previous papers before so it will appear this time.
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    So if a hydrogen is connected to a C that is also connected to 2 other carbons with different functional groups on each side, the splitting would be a multiplet, what if the neighbouring groups are not carbon? would the splitting be a multiplet still?
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    (Original post by itsConnor_)
    I'm thinking triglycerides/fatty acids in some form. Hasn't come up in 3 years

    trans fats increase low density lipoproteins/'bad cholesterol' and lead to coronary heart disease / strokes
    definition of high and low density lipoproteins might come up
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    (Original post by itsConnor_)
    I'm thinking triglycerides/fatty acids in some form. Hasn't come up in 3 years

    trans fats increase low density lipoproteins/'bad cholesterol' and lead to coronary heart disease / strokes
    Oooh ok maybe biodisel too?
    And the polarised light thing to do with optical isomers.
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    (Original post by lai812matthew)
    cuz it never came up in any papers before, and the exam board will try to catch people out with things that are never examined before. another thing i thought is how to distinguish a compound with stereoisomers and a compound without it. the answer is plane polarised light. and the racemic mixture thingy. it appears at AQA every year but never in OCR even though it is in the textbook!
    what's racemic mixture??
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    (Original post by tcameron)
    what's racemic mixture??
    each amounts of all isomers ( bk p. 53)
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    (Original post by bakedbeans247)
    Oooh ok maybe biodisel too?
    And the polarised light thing to do with optical isomers.
    Using methanol?

    One optical rotates plane polarised light anti-clockwise and the other clockwise?

    A racemic mixture contains equal amounts of each optical isomer and hence the rotations of plane polarised light cancel each other out? Never seen a racemic mixture question on OCR A actually...
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    Don't think so - Standard alcohols don't readily lose the H-atom from their -OH group in solution so they shouldn't react.
    Phenol is a special case because the H-atom in the -OH group dissociates in water, giving it slightly acidic properties.
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    Will they mark an annotated nmr spec??
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    From an Edexcel paper: make sure you can do part b) https://gyazo.com/8a665c8cf026cc6c9c909a736f7df0c4

    part a) could come up as application of knowledge but they'd prob give some other info
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    (Original post by itsConnor_)
    Using methanol?

    One optical rotates plane polarised light anti-clockwise and the other clockwise?

    A racemic mixture contains equal amounts of each optical isomer and hence the rotations of plane polarised light cancel each other out? Never seen a racemic mixture question on OCR A actually...
    Methanol used because it is renewable and is always in excess to shift the equilibrium to the right/reaction to go into completion
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    (Original post by itsConnor_)
    From an Edexcel paper: make sure you can do part b) https://gyazo.com/8a665c8cf026cc6c9c909a736f7df0c4

    part a) could come up as application of knowledge but they'd prob give some other info
    do you have the answers for this question?
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    exam board seems to like giving an example of a reaction that is not in the syllabus , and ask you to draw the reagent for a similar reaction. like last years benzene's nucleophilic substitution ,and ozonolysis some years ago lol
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    (Original post by tcameron)
    Methanol used because it is renewable and is always in excess to shift the equilibrium to the right/reaction to go into completion
    Yep, worth a look over the Jan 11 question https://gyazo.com/cc2009d528a5470b4048d02353e1fb90
 
 
 
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