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    (Original post by kevloui)
    Shouldn't be, rain should be able to hydrolyse it just fine :P

    p-orbitals overlap to form pi bonds, creating electron clouds above and below the plane. All the bonds are the same and are therefore the same length.
    hahaha true


    correct

    my turn
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    hi guys do we need to know how to make tollens reagent? and if so...how is it done?

    cheers
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    (Original post by otrivine)
    hahaha true


    correct

    my turn
    Explain what it is meant by the Mobile Phase

    (Original post by mrmccarl)
    hi guys do we need to know how to make tollens reagent? and if so...how is it done?

    cheers
    Yes you do, Its made by reacting Silver Nitrate with Ammonia, with heat
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    (Original post by kevloui)
    Explain what it is meant by the Mobile Phase



    Yes you do, Its made by reacting Silver Nitrate with Ammonia, with heat
    thanks mate
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    (Original post by kevloui)
    Explain what it is meant by the Mobile Phase



    Yes you do, Its made by reacting Silver Nitrate with Ammonia, with heat
    Mobile phase is the phase in which the chromatography move
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    Just did Jan 2013 and got 56/60!! If only this result would happen on Wednesday then I'll be set!!
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    (Original post by MathsNerd1)
    Just did Jan 2013 and got 56/60!! If only this result would happen on Wednesday then I'll be set!!
    I need 85/90 UMS so on that paper I'd need 60/60.


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    (Original post by Mus1995)
    I need 85/90 UMS so on that paper I'd need 60/60.


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    My god!! Best of luck with that and I need as high as possible to get my A grade and maybe the A* grade, so I'm going to just aim for 56+ and a hardish paper to make up for it
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    Actually you don't need to know how to make tollen's reagent - it used to be on the old spec but now its not on this spec.
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    (Original post by MathsNerd1)
    My god!! Best of luck with that and I need as high as possible to get my A grade and maybe the A* grade, so I'm going to just aim for 56+ and a hardish paper to make up for it
    I need 29/90 for an A. :P so if I miss the A* I can still fail the paper and get an A.

    The coursework ****ed me over. 36/40 raw looking to be around 48/60 UMS. 4 raw marks for 12 UMS. Ridiculous. :/


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    This may sound silly, but how do you actually draw Optical isomers of Chiral Carbons, i always seem to get the functional groups on the wrong sides, is there a general rule?
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    (Original post by Mus1995)
    I need 29/90 for an A. :P so if I miss the A* I can still fail the paper and get an A.

    The coursework ****ed me over. 36/40 raw looking to be around 48/60 UMS. 4 raw marks for 12 UMS. Ridiculous. :/


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    That's just not fair! I need like a high A just to guarantee my A -.- This is getting back at me for getting a C last year and yeah I got the same coursework mark too :-/
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    Heres a question for you all:

    What conditions/reagents are required to prepare propylamine from 1-chloropropane? [2]

    Suggest a possible disadvantage of using this method and state one possible way to avoid this. [2]

    Suggest two reasons why water cannot be used as a solvent in this reaction. [2]
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    (Original post by thers)
    Heres a question for you all:

    What conditions/reagents are required to prepare propylamine from 1-chloropropane? [2]

    Suggest a possible disadvantage of using this method and state one possible way to avoid this. [2]

    Suggest two reasons why water cannot be used as a solvent in this reaction. [2]
    Excess NH3 and ethanol solvent. Heat under reflux.

    The byproduct HCl/NH4+Cl- is acidic? So it needs to be neutralised with a base which you have, NH3? I dunno.

    An ethanol solvent is used instead of water. Is it because it would interact with HCl? Dipoles etc.


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    (Original post by thers)
    Heres a question for you all:

    What conditions/reagents are required to prepare propylamine from 1-chloropropane? [2]

    Suggest a possible disadvantage of using this method and state one possible way to avoid this. [2]

    Suggest two reasons why water cannot be used as a solvent in this reaction. [2]
    1) Reagents= excess (conc) NH3 and ethanol as solvent, conditions= heat under reflux

    2) can undergo further multiply nucleophilic substitution so does not give the desired product , a possible way to avoid this is to add excess NH3 to minimise further substitution


    3) Because addition of water will result in hydrolysis and could split the propylamine/1-chloropropane into 2 monomers, h2o does not result in the amine forming , as no nitrogen is present in H2O
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    Both right on first part
    Second part otrivine is correct
    Third part is because water can act as a nucleophile so hydrolysis could take place forming an unwanted alcohol. I was only supposed to put one reason, not two - my mistake.
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    (Original post by thers)
    Both right on first part
    Second part otrivine is correct
    Third part is because water can act as a nucleophile so hydrolysis could take place forming an unwanted alcohol. I was only supposed to put one reason, not two - my mistake.
    So was I correct about the hydrolysis then?
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    (Original post by otrivine)
    So was I correct about the hydrolysis then?
    Yes.

    Describe a test to verify if a carboxylic acid is present in a mixture of alcohols, phenols and carboxylic acids. [3]
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    (Original post by thers)
    Yes.

    Describe a test to verify if a carboxylic acid is present in a mixture of alcohols, phenols and carboxylic acids. [3]
    add na2co3

    should produce a gas.

    so fizzing should be seen within the reaction.
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    (Original post by thers)
    Yes.

    Describe a test to verify if a carboxylic acid is present in a mixture of alcohols, phenols and carboxylic acids. [3]

    adding Na2co3, and what happens in this process the OH ---> O-Na+ , and you co2 and water is released, observation = fizzing
 
 
 
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