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    (Original post by otrivine)
    I dont think chemical tests will be asked, as it was quite heavy in the Jan paper! sadly



    Describe transesterification
    Hm.. true, but OCR do whatever they like. I guess we just don't know, It's hard to predict for this paper, because there isn't alot of content.

    exchanging the organic group of an ester with the organic group R of an alcohol.

    What is required required to convert bromoethane into methylamine?
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    (Original post by kevloui)
    Hm.. true, but OCR do whatever they like. I guess we just don't know, It's hard to predict for this paper, because there isn't alot of content.

    exchanging the organic group of an ester with the organic group R of an alcohol.

    What is required required to convert bromoethane into methylamine?


    True

    I thought transesterfication is the process of reacting triglycerides with either methanol or ethanol as they are renewable under the presence of NaOH or KOH catalyst to give biodiesel and glycerol ?



    To convert bromoethane to methylamine, the reagents are excess NH3 and ethanol as solvent and condition heat under reflux
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    (Original post by otrivine)
    I thought transesterfication is the process of reacting triglycerides with either methanol or ethanol as they are renewable under the presence of NaOH or KOH catalyst to give biodiesel and glycerol ?
    It is. He over simplified it. :P




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    (Original post by Mus1995)
    It is. He over simplified it. :P




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    I see!

    you with these draw impure structures,

    is it any structure you can draw and get a mark
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    (Original post by otrivine)
    True

    I thought transesterfication is the process of reacting triglycerides with either methanol or ethanol as they are renewable under the presence of NaOH or KOH catalyst to give biodiesel and glycerol ?



    To convert bromoethane to methylamine, the reagents are excess NH3 and ethanol as solvent and condition heat under reflux
    Is that the definition in the book? I just said the definition I once heard.

    And yess perfect, my turn
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    (Original post by Mus1995)
    It is. He over simplified it. :P




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    Simplicity is fun.. Except in OCR exams
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    (Original post by kevloui)
    Is that the definition in the book? I just said the definition I once heard.

    And yess perfect, my turn
    I see Good!!


    State the features of Proton NMR that allows you to identify the structure
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    (Original post by otrivine)
    I see Good!!


    State the features of Proton NMR that allows you to identify the structure
    Multiplicity:- N+1 with number of H+ on adjacent carbon
    Integration:- Number of H+ on corresponding carbon
    Chemical shift:- Identification of the chemical environment

    Explain what you will see on a benzene HNMR
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    (Original post by kevloui)
    Why??? You guys have been on here doin loads of stuff, I've just been waiting for this exam to come and go.
    Same. Just waiting. Not particularly confident, just want it over with so I can focus on the holidays before unay
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    (Original post by kevloui)
    Multiplicity:- N+1 with number of H+ on adjacent carbon
    Integration:- Number of H+ on corresponding carbon
    Chemical shift:- Identification of the chemical environment

    Explain what you will see on a benzene HNMR
    correct



    In benzene proton NMR, you would expect, there to be a chemical shift 6.5-8ppm and 1 peak which shows a doublet, , so 1 hydrogen atom adjacent to carbon atom.
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    (Original post by otrivine)
    I see!

    you with these draw impure structures,

    is it any structure you can draw and get a mark
    I don't understand. Elaborate?


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    (Original post by Mus1995)
    I don't understand. Elaborate?


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    OKay in 2 past papers I saw , they ask you to draw an impure structure, how would we know if we did it correctly or not? Is it any structure
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    (Original post by _HabibaH_)
    Same. Just waiting. Not particularly confident, just want it over with so I can focus on the holidays before unay
    Ahh man I can't wait!

    (Original post by otrivine)
    correct



    In benzene proton NMR, you would expect, there to be a chemical shift 6.5-8ppm and 1 peak which shows a doublet, , so 1 hydrogen atom adjacent to carbon atom.
    Nice onneee!
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    (Original post by kevloui)
    Ahh man I can't wait!



    Nice onneee!
    Give the roles of TMS,CDCL3,D2O
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    (Original post by otrivine)
    OKay in 2 past papers I saw , they ask you to draw an impure structure, how would we know if we did it correctly or not? Is it any structure
    Oh. We'll look at what I posted for both of them. You just further substitute on the amine group.

    You know how if you have RCl + 2NH3 -----> (ethanol solvent) RNH2 + NH4(+)Cl(-)

    This is the product you usually form in the first part of the question. The next part asks you for the impurity.

    All do you is take the RNH2 and substitute a H for another R by the same reaction above. You can do this until no Hydrogen atoms remain. You label the amine like this:

    NH3 - ammonia

    NH2 - primary amine

    NH - secondary amine

    N - Tertiary amine

    Where H's are replaced with different/the same R groups. Like RNH2 and 2RNH etc

    To check your impurity is right just look at the molecular formula they provide and compare it to your structure.

    One second ill post the Chem guide page


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    (Original post by Mus1995)
    Oh. We'll look at what I posted for both of them. You just further substitute on the amine group.

    You know how if you have RCl + 2NH3 -----> (ethanol solvent) RNH2 + NH4(+)Cl(-)

    This is the product you usually form in the first part of the question. The next part asks you for the impurity.

    All do you is take the RNH2 and substitute a H for another R by the same reaction above. You can do this until no Hydrogen atoms remain. You label the amine like this:

    NH3 - ammonia

    NH2 - primary amine

    NH - secondary amine

    N - Tertiary amine

    Where H's are replaced with different/the same R groups. Like RNH2 and 2RNH etc

    To check your impurity is right just look at the molecular formula they provide and compare it to your structure.

    One second ill post the Chem guide page


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    thanks but the book shows the product as HCL??
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    (Original post by otrivine)
    thanks but the book shows the product as HCL??
    Read this http://www.chemguide.co.uk/organicpr...ation.html#top

    Ah you'd think. And as I have shown/you can see HCl (aq) is formed from the H and Cl.


    However. You need EXCESS ammonia for this reaction. So the ion NH4(+)Cl(-) ion will form. It is very unlikely you will be left with HCl!


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    Can someone help me, I've just done a past paper from June 2010 and there's a question that tells me to write an equation on hydroxyethanal HOCH2CHO with an oxidising agent [O] and the mark scheme gives HOCH2CHO + 3[O] > HOOCCH2COOH + H2O the oxygen atoms balance out but the hydrogens don't?
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    (Original post by mus1995)
    Attachment 227220

    here you go. Ask if you don't understand/can't read anything.


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    thankyou!
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    (Original post by Mus1995)
    Bit messy. It's another further substitution. Attachment 227223


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    This helps so much thankyou!
 
 
 
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