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    (Original post by Mus1995)
    I do.

    Show me a question and I'll show you how to do it.


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    Jan 2010- 5b II
    Impurity with molecular formula C10H11NO3
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    should we draw the structure in [ ] when they say draw two repeated units of a polymer?
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    (Original post by NinjaNerdfighter)
    It's the january 2011 paper, question 4aii

    http://www.ocr.org.uk/Images/58126-q...d-analysis.pdf
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    Here you go. Ask if you don't understand/can't read anything.


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    (Original post by amin666)
    should we draw the structure in [ ] when they say draw two repeated units of a polymer?
    Yeah. Like this. Name:  ImageUploadedByStudent Room1371394591.763824.jpg
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Size:  130.1 KB


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    (Original post by Mus1995)
    Yeah. Like this. Name:  ImageUploadedByStudent Room1371394591.763824.jpg
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Size:  130.1 KB


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    what does the "n" stand for and does it have to be included?
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    (Original post by Onkar-M)
    Jan 2010- 5b II
    Impurity with molecular formula C10H11NO3
    Bit messy. It's another further substitution. Name:  ImageUploadedByStudent Room1371395050.846405.jpg
Views: 499
Size:  128.3 KB


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    (Original post by Mus1995)
    Yeah. Like this. Name:  ImageUploadedByStudent Room1371394591.763824.jpg
Views: 421
Size:  130.1 KB


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    I always used to draw the brackets but the mark schemes always say to ignore so I've stopped. Might do it in the exam though just in case they want it in our paper.

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    (Original post by D4rth)
    I always used to draw the brackets but the mark schemes always say to ignore so I've stopped. Might do it in the exam though just in case they want it in our paper.

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    It says ignore which means you can do it, it won't dock you marks. I think it is good practice. You will still get the marks!

    (Original post by kuku2013)
    what does the "n" stand for and does it have to be included?
    It represents the fact this repeat unit continues n times, as it is a long polymer! So just imagine this repeat unit continuing.
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    Guys can anyone tell me all the reactions you need to remember ?? And the conditions for each one please ??
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    (Original post by Mus1995)
    Can you link me to the paper? I need to see the question.


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    http://www.ocr.org.uk/Images/58126-q...d-analysis.pdf

    Question 4a(ii)
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    (Original post by tom2013)
    Guys can anyone tell me all the reactions you need to remember ?? And the conditions for each one please ??
    I've attached a list of all the conditions and reagents I've been using to revise, think almost everything is covered in there

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    You can probably ignore the first one


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    (Original post by amsss)
    I've attached a list of all the conditions and reagents I've been using to revise, think almost everything is covered in there

    Name:  ImageUploadedByStudent Room1371397356.786392.jpg
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    Hey, is the free radical equation on the spec? Because it's nowhere in the book or in the new spec questions? Thanks.
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    (Original post by _HabibaH_)
    Hey, is the free radical equation on the spec? Because it's nowhere in the book or in the new spec questions? Thanks.
    I'm not sure it actually is, we were just told it should be assumed knowledge from AS. Don't think I've seen any questions on it though so wouldn't worry about it to be honest


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    (Original post by Mus1995)
    Bit messy. It's another further substitution. Name:  ImageUploadedByStudent Room1371395050.846405.jpg
Views: 499
Size:  128.3 KB


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    Thank you!
    Ps nice emoticons . Haha
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    (Original post by tom2013)
    Guys can anyone tell me all the reactions you need to remember ?? And the conditions for each one please ??
    There are LOADS so forgive me if I miss any.

    Nitration of Benzene: C6H6 + Concentrated HNO3 ==> C6H5NO2 + H+
    Conditions: Reflux + Concentrated H2SO4 Catalyst
    Formation of electrophile: H2SO4 + HNO3 ==> HSO4- + NO2+ = H2O
    How the catalyst works: H+ = HSO4- ==> H2SO4
    Halogenation of Benzene: C6H6 + Cl2/Br2 ==> C6H5Cl/C6H5Br + HCl/HBr
    Conditions: AlCl3/AlBr3 Catalyst
    Reduction of Nitrobenzene: C6H5NO2 + Sn/Conc. HCl (6[H]) ==> C6H5NH2 + 2H2O
    Conditions: Reflux
    Diazotisation: C6H5NH2 + Concentrated HCl + Concentrated HNO2 ==> C6H5N2+Cl- + H2O
    Conditions: Under 10 degrees celcius
    Coupling: C6H5N2+Cl- + Phenol ==> Azo Dye
    Conditions: Alkaline conditions, under 10 degrees celcius

    Test for Carbonyls: Add 2,4-DNPH forms orange precipitation which is addition-elimination reaction
    Identifying carbonyl: Filter and recrystallise the precipitate and measure melting point, compare against known values.
    Distinguishing Aldehyde or Ketone: Add Tollen's reagent which forms a silver mirror if aldehyde is present.
    Reducing aldehydes/ketones: Add NaBH4 which is Nucleophilic addition reaction

    Formation of polyester: Carboxylic acid + alcohol monomers
    Formation of polyamide: Carboxylic acid + amine monomers

    Primary Alcohol + [O] ==> Aldehyde (Distillation)
    Primary Alcohol + 2[O] ==> Carboxylic acid (Reflux)
    Secondary Alcohol + [O] ==> Ketone (Reflux)

    Halogenation of alkenes: Add HCl/HBr??
    Test for Alkenes: Add Br2 ==> Colour changes from orange to colourless
    Test for Phenol (or any OH group): Add Na ==> Effervescent produced as Hydrogen released
    Phenol + Br2 ==> 2,4,6-tribromophenol (white precipitate)

    Fatty acid + Glycerol ==> Triglyceride

    Acid Hydrolysis: Add H2O with presence of acid catalyst under reflux
    Alkaline Hydrolysis: Add NaOH in alkaline conditions

    My brain's gone blank haha maybe others could add? Hope this helps, sorry if I made any mistakes.
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    hey do we have to describe how to prepare single chiral isomers or can we just state the name of the methods such as chiral synthesis and using enzymes?
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    (Original post by Chriswhjay)
    Can ANYONE please outline how to assemble a high resolution proton NMR or give any advice?! Im dreading seeing a 10 mark question and not getting the right shape! I can analyse it correctly and all, its just putting it together, it always goes wrong D;
    This guy explains it really well:

    http://www.youtube.com/watch?v=k6F__pysc74

    But if you're just having trouble putting it all together maybe it's just a case of practising trial and error? Or it could be something in your technique of tackling the question which may make it difficult for you to determine a structure. After watching this guy teach it (and there's another video about combined techniques) I love doing those 10 markers, was so gutted that they didn't come up in jan!

    EDIT: I've added some worksheets that have lots of proton and carbon NMR questions for anyone who wants to practice.
    Attached Images
  1. File Type: pdf NMR Test 10.pdf (438.3 KB, 111 views)
  2. File Type: pdf NMR Test 10 Mark Scheme.pdf (428.3 KB, 76 views)
  3. File Type: pdf NMR Worksheet.pdf (428.2 KB, 72 views)
  4. File Type: pdf C13 NMR Q.pdf (126.1 KB, 77 views)
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    (Original post by amsss)
    I've attached a list of all the conditions and reagents I've been using to revise, think almost everything is covered in there

    Name:  ImageUploadedByStudent Room1371397356.786392.jpg
Views: 480
Size:  182.5 KB

    You can probably ignore the first one


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    Nice, but is KCN/H+ stuff still in our spec?

    BTW, question for anyone. Saw in an old paper; "Compound B is a saturated hydrocarbon and the NMR of compound B contains just one peak." The answer btw is that Compound B is an alkane, so how does an alkane only have one peak, wouldn't it have 2 chemical environments? C-CH2-C and C-CH3?
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    Did my first past paper and got 55/60 on Jan 2010, I'm hoping to race through another two tonight and the rest tomorrow and Tuesday night! Hopefully this A/A* is still capable
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    I'm doing this paper. I much prefer this module in comparison with F325 in Jan and the past papers are relatively easy in comparison. Hoping for a very hard proton NMR question - it's very satisfying piecing together the unknown compound at the end of the paper.
 
 
 
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