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    (Original post by MathsNerd1)
    C6H6 + HNO3 (conc sulphuric acid catalyst) ---> C6H5NO2 + H20 and I'm not sure about the atom economy, would it be 50%?
    Atom economy is 87.4% ??
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    (Original post by sals1234)
    Hey guys, can someone please explain to me why in question 5biv (feature that causes stereoisomersism in citral) we have to circle the double bond that's on the right and not the one on the left? Here's the link to the paper: http://www.ocr.org.uk/Images/58126-q...d-analysis.pdf

    Thank you
    with the one on the left, the lefter carbon is attached to 2 ch3 groups therefore it has no isomerism
    basically if you rotate the two groups you still have the exact same thing therefore it must be the on the right
    hope this helps kinda
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    (Original post by Onkar-M)
    So TLC - adsorption, G-C = rel. solubility?
    Satsriakal Ji!

    Substances adsorb onto a SOLID stationary phase, but are separated by RELATIVE SOLUBILITY on a liquid stationary phase.

    TLC- Solid- Adsorption
    GC- Liquid- Rel. Solubility.

    But, if i'm not mistaken, can't GC also have a solid inert support, thus separating by adsorption?
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    (Original post by Jodie_668)
    Because the carbon that is on the left on the double bond of the left (I hope that makes sense, ahaha) is bound to the same groups (bound to two CH3). For E/Z isomerism, each carbon in the C=C must be bound to two different groups.
    Ah thank you!!
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    good luck everyone with the exam tomorrow
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    Hi, does anyone know if when you hydrolysis peptide of amide bonds using acid, does the NH2 become +NH3? Some of my notes say that it does and others don't
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    (Original post by MathsNerd1)
    Thanks and yeah I remember that, just thought you wanted a value instead
    That's not the answer - it was a hint to how you work out the atom economy so you can now work out the value.
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    (Original post by Onkar-M)
    So TLC - adsorption, G-C = rel. solubility?
    GC depends on the state of the stationary phase. if it's solid, adsorption. If it's liquid, relative solubility. Read the state but usually it is a liquid state.
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    (Original post by k54g00)
    Satsriakal Ji!

    Substances adsorb onto a SOLID stationary phase, but are separated by RELATIVE SOLUBILITY on a liquid stationary phase.

    TLC- Solid- Adsorption
    GC- Liquid- Rel. Solubility.

    But, if i'm not mistaken, can't GC also have a solid inert support, thus separating by adsorption?
    Yes you are right GC can separate components with either adsorption or rel solubility...depends what stationary phase the paper tells you.
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    (Original post by Jodie_668)
    Hi, does anyone know if when you hydrolysis peptide of amide bonds using acid, does the NH2 become +NH3? Some of my notes say that it does and others don't
    yes it becomes nh3+ due to 2h+ from the acid and h2o.
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    (Original post by thers)
    That's not the answer - it was a hint to how you work out the atom economy so you can now work out the value.
    Okay then, thanks Do you have any other questions for me to tackle?
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    (Original post by Jodie_668)
    Hi, does anyone know if when you hydrolysis peptide of amide bonds using acid, does the NH2 become +NH3? Some of my notes say that it does and others don't
    If acid is in excess, then yes it will. If it is not excess, then no it won't. If the amount is not specified then they should take either answer.
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    (Original post by mrmccarl)
    Yes you are right GC can separate components with either adsorption or rel solubility...depends what stationary phase the paper tells you.
    How much further detail do we need to know including limitation and retention time?
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    (Original post by MathsNerd1)
    Okay then, thanks Do you have any other questions for me to tackle?
    What two observations would you see if you reacted bromine with phenol?
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    (Original post by Varsh05)
    Atom economy is 87.4% ??
    Hi, how did you work out that atom economy? And are there any other AS equations that I should know? Thank you in advance
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    (Original post by mrmccarl)
    yes it becomes nh3+ due to 2h+ from the acid and h2o.

    (Original post by _HabibaH_)
    If acid is in excess, then yes it will. If it is not excess, then no it won't. If the amount is not specified then they should take either answer.
    Thanks so much!
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    (Original post by thers)
    What two observations would you see if you reacted bromine with phenol?
    The bromine water would be decolourised and a white precipitate will be formed?
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    (Original post by Varsh05)
    Atom economy is 87.4% ??
    Yes
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    So panicked- desperately in need of an A* tomorrow to make my offer since c4 kicked my a** today. Hopefully tomorrow will be a nice paper and I won't make any of my patented mistakes:rolleyes:
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    Have they actually ever asked for the polymers of Kevlar/Terylene/Nylon-6,6 or PLA??
 
 
 
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