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    (Original post by otrivine)
    on page 84

    do you want me to describe spin as to how many hydrogens are found adjacent to carbon ato,m
    Yeah that's what I was hinting at when I said in proton NMR, sorry if it wasn't too clear


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    (Original post by MathsNerd1)
    Yeah that's what I was hinting at when I said in proton NMR, sorry if it wasn't too clear


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    oh ok sorry

    so spin-spin gives the indication of the number of hydrogen atoms adjacent to carbon atoms and there are peaks in which could vary and represent the number of H , examples are singlet,doublet,triplet , quartet or multiplet

    singlet=no H adjacent to carbon
    doublet= 1 H adjacent to carbon
    triplet= 2 H adjacent to Carbon
    quartet= 3 H adjacent on carbon
    multiplet= 4+ H adjacet to carbon
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    (Original post by otrivine)
    oh ok sorry

    so spin-spin gives the indication of the number of hydrogen atoms adjacent to carbon atoms and there are peaks in which could vary and represent the number of H , examples are singlet,doublet,triplet , quartet or multiplet

    singlet=no H adjacent to carbon
    doublet= 1 H adjacent to carbon
    triplet= 2 H adjacent to Carbon
    quartet= 3 H adjacent on carbon
    multiplet= 4+ H adjacet to carbon
    Correct.


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    (Original post by MathsNerd1)
    Correct.


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    Why is there different chemcal shift values (1)
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    (Original post by otrivine)
    Why is there different chemcal shift values (1)
    To show that there are different chemical environments?


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    (Original post by MathsNerd1)
    To show that there are different chemical environments?


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    because of different electronegativty between atoms

    my turn
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    (Original post by otrivine)
    because of different electronegativty between atoms

    my turn
    Oh I see and this will be the last from me, need to do a Maths paper under times conditions

    Ethyl Methanoate is one of the compounds responsible for the smell of raspberries. Outline, with reaction conditions, how it could be synthesised in the lab from Methanol. (7)


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    (Original post by MathsNerd1)
    Oh I see and this will be the last from me, need to do a Maths paper under times conditions

    Ethyl Methanoate is one of the compounds responsible for the smell of raspberries. Outline, with reaction conditions, how it could be synthesised in the lab from Methanol. (7)


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    Firstly, methanol is a primary alcohol and is therefore, oxidised to a carboxylic acid via heating under relux, with acidified potassium dichromate and concentrated H2SO4 and forms methaoic acid, the methanoic acid then has to react with an alochol and a catalyst would be needed in this concentratied H2SO4 (H+(aq)) and should be heated in a water bath. Methanoic acid reacts with ethanol and undergoes a condensation reaction in which a molecule of water is removed and water would be formed as product. This causes them to join together and forms an ester which is Ethyl Methanoate and this gives rise to the smell of rasberries.

    N.B when potassium dichromate is acifiied oxidised colour changes from organe to green
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    (Original post by otrivine)
    Firstly, methanol is a primary alcohol and is therefore, oxidised to a carboxylic acid via heating under relux, with acidified potassium dichromate and concentrated H2SO4 and forms methaoic acid, the methanoic acid then has to react with an alochol and a catalyst would be needed in this concentratied H2SO4 (H+(aq)) and should be heated in a water bath. Methanoic acid reacts with ethanol and undergoes a condensation reaction in which a molecule of water is removed and water would be formed as product. This causes them to join together and forms an ester which is Ethyl Methanoate and this gives rise to the smell of rasberries.

    N.B when potassium dichromate is acifiied oxidised colour changes from organe to green
    Correct.


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    (Original post by otrivine)
    Are you breaking up with me

    I thought we were good buddies
    Ha. No! You probably just didn't see my question.
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    (Original post by MathsNerd1)
    Correct.


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    ok

    Define: esterification
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    (Original post by MasterYi)
    Ha. No! You probably just didn't see my question.
    oh ok
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    (Original post by otrivine)
    oh ok
    1) explain why triglycerides are soluble in non polar solvents and not in water [3]
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    Hey guys, I posted this in the F325 thread, if anyone could help that would be great. Thanks!

    Spoiler:
    Show
    (Original post by kimsiclez)
    Could someone please help me in regards to the rate-determining step?
    Does it always have to be the first step in the mechanism of the reaction?

    eg. for 2NO2 + O2 = 2NO2
    rate = k[NO]2

    For the mechanism I put:
    O2 + N2 = N2O2
    N2O2 + 2NO = 2NO2 + N2

    But the answer is:
    2NO = N2O2
    N2O2 + O2 = NO2

    So does the slow step mechanism always happen first and is followed by the fast steps? I thought it didn't matter, so please someone tell me if I'm wrong!
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    (Original post by Zzzyax)
    1) explain why triglycerides are soluble in non polar solvents and not in water [3]
    Triglycerides are long chain carbon bonds and atoms and contains no OH group for it to dissolve in water as hydrogen bonds are not formed
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    (Original post by otrivine)
    Triglycerides are long chain carbon bonds and atoms and contains no OH group for it to dissolve in water as hydrogen bonds are not formed

    • do not form good hydrogen bonds,




    • due to lack of oxygen atoms in hydrocarbon chain




    • form van der waals forces between trigylcerides
    • and non polar solvent




    • long hydrocarbon chains do not hydrogen
      bond/would interfere with hydrogen bonding in water
      AW
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    I just did my first F324 past paper, i got 45/60, ran out time abit, you have to do this exam so fast, its like a ****ing speed test, how fast can you write, in this exam you cannot afford to waste a single moment daydreaming or whatever, you must be almost relentless in the speed you write, and be absolutely focused all the time, cause youll need every second in this exam , yes they have given an extra 15 mins, (but as shown in jan F325), they have made the papers harder or increased the grade boundaries, (think about it there are not just going to given extra time and thats it because its unfair of people in previous years), anyway over the next month im going to do the rest of the papers and perhaps post what i get here.
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    Hey people, Im wondering if anyone has got a big compilation of questions? Especially those on the old spec which are still relevant. If people dont mind posing one it could be very useful?
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    (Original post by BIG Y)
    Hey people, Im wondering if anyone has got a big compilation of questions? Especially those on the old spec which are still relevant. If people dont mind posing one it could be very useful?
    Master Yi posted a link before http://www.thestudentroom.co.uk/show...6#post42165206
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    (Original post by D4rth)
    Master Yi posted a link before http://www.thestudentroom.co.uk/show...6#post42165206
    cheers man!
 
 
 
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