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    (Original post by EwaHum)
    you both answered at the same time sorry for taking both of your time up but thanks a lot to both all of you.
    Np
    I check this thread more frequently than chemistry forums as I have it on my subscription

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    Happy yo help
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    Id love to know how everybody is revising? I'm finding it slightly overwhelming especially unit 2, although I put that down to my awful teacher. She taught us the last module in 30 minutes!!!!!
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    (Original post by Georgiam247)
    Id love to know how everybody is revising? I'm finding it slightly overwhelming especially unit 2, although I put that down to my awful teacher. She taught us the last module in 30 minutes!!!!!
    Lol, the last module is very small though.

    All you really need to know is that co2 isnt all bad, you need to know how the ozone layer works and about catalytic converters and ccs. That's all :yes:

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    Hey has any one done the evaluative 15 mark chemistry practical yet? I'm confused on what we need to prepare for. My friends said that they went over calculations on moles, molar mass etc and just went through the basics. Does anyone have an idea? Thanks.
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    when you say sth is being oxidised or reduced, do you say the element of the compound or the compound?
    e.g. the S in SO2 is reduced / SO2 is reduced?

    thank you!
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    Can someone explain the free radical substitution of the following reaction:

    CHF3 + Cl2 ----->CClF3 +HCl

    Don't understand the propagation stage.
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    (Original post by Super199)
    Can someone explain the free radical substitution of the following reaction:

    CHF3 + Cl2 ----->CClF3 +HCl

    Don't understand the propagation stage.
    Do you know what the propagation stages are? If so post them so I can check I've done them right then I will explain

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    (Original post by samb1234)
    Do you know what the propagation stages are? If so post them so I can check I've done them right then I will explain

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    Na I don't sorry.
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    (Original post by Super199)
    Na I don't sorry.
    My guess is CHF3 +Clradical goes to HCl + CF3 radical.

    CF3 radical +cl2 goes to CClF3 +cl radical

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    (Original post by Super199)
    Can someone explain the free radical substitution of the following reaction:

    CHF3 + Cl2 ----->CClF3 +HCl

    Don't understand the propagation stage.
    Initiation: Cl-Cl -> 2Cl.
    propagation I: CHF3 + Cl. -> HCl + CF3.
    propagation II: CF3. + Cl2 -> CF3Cl + Cl.
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    (Original post by C0balt)
    Initiation: Cl-Cl -> 2Cl.
    propagation I: CHF3 + Cl. -> HCl + CF3.
    propagation II: CF3. + Cl2 -> CF3Cl + Cl.
    So in the first step the hydrogen gets knocked off. The second step a chlorine binds with the radical?
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    (Original post by Super199)
    So in the first step the hydrogen gets knocked off. The second step a chlorine binds with the radical?
    Yes in propagation steps a new radical is regenerated.
    C-F bond is too strong for F to get knocked off

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    Been doing unit 1 papers and have been getting A's consistently, yesterday I got 69/70!

    Then I tried doing a unit 2 paper...
    Not so good.

    Anyone know any good ways to revise last minute and any sites with good notes? EASY notes?
    I have exactly one month until my unit 2 paper and only 3 weeks until my unit 1 paper.
    I am WIGGING OUTTTTTTT
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    (Original post by grapes12)
    Been doing unit 1 papers and have been getting A's consistently, yesterday I got 69/70!

    Then I tried doing a unit 2 paper...
    Not so good.

    Anyone know any good ways to revise last minute and any sites with good notes? EASY notes?
    I have exactly one month until my unit 2 paper and only 3 weeks until my unit 1 paper.
    I am WIGGING OUTTTTTTT
    Board?

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    Hey, anyone doing OCR A, I'm currently revising reactions of alkenes and on p130 of the OCR-heinemann textbook when talking about the addition of hydrogen halides to alkenes, it says "hydrogen halides are gases at room temperature and are bubbled into liquid alkanes"..... Did they mean liquid alkenes?!? My brain is dying
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    just did the bio empa, it was ok anyone done the chemistry one?
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    Anyone have any tips on good ways to revise chemistry? I'm really struggling. Plain reading the book isn't working and with making notes I tend to waste a lot of time getting it all neat and pretty and end up not getting much in my head, plus it's really quite late stage to be making notes now. I also didn't want to do papers till later because there aren't many so I want to save them. What do I do???
    Spoiler:
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    I actually haven't even learnt the majority of the content either :cry: I'm selfstudying it and left it soooo late I know
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    (Original post by jadys10)
    Anyone have any tips on good ways to revise chemistry? I'm really struggling. Plain reading the book isn't working and with making notes I tend to waste a lot of time getting it all neat and pretty and end up not getting much in my head, plus it's really quite late stage to be making notes now. I also didn't want to do papers till later because there aren't many so I want to save them. What do I do???
    Spoiler:
    Show
    I actually haven't even learnt the majority of the content either :cry: I'm selfstudying it and left it soooo late I know
    hey same here. but ive started. u need to make notes. just try not care much about the neatness etc. but I do. and just make notes from syllabus points. and u can do past papers and later u can just make urself a test out of all their mixtures
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    (Original post by jadys10)
    Anyone have any tips on good ways to revise chemistry? I'm really struggling. Plain reading the book isn't working and with making notes I tend to waste a lot of time getting it all neat and pretty and end up not getting much in my head, plus it's really quite late stage to be making notes now. I also didn't want to do papers till later because there aren't many so I want to save them. What do I do???
    Spoiler:
    Show
    I actually haven't even learnt the majority of the content either :cry: I'm selfstudying it and left it soooo late I know

    You MUST do papers, my advice is save 2 full papers for the 2 weeks before the exam, and do the rest for revision. There's really no point in saving the papers since the whole point of doing them is to assess your strengths and weaknesses. Papers papers papers theyre literally the most important resource. As for note taking, you're right about it taking too long; read a chapter from the book, highlight important bits, then make posters summarising, and use flash cards to get the info into your LTM!! Don't be worried just calmly work through it good luck
 
 
 
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