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    (Original post by Muaaz98)
    http://www.thestudentroom.co.uk/show....php?t=3327991
    Still hunting TSR for C3 Markscheme
    If you find one hit me up
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    (Original post by Pra99)
    Yeh less hydrogen iodide, more hydrogen and iodine as forward reaction is endothermic
    Literally, I could cry right now, I've screwed up so many answers and was so confident about chemistry, Id be absolutely deighted with an A now.
    So angry.
    guess I'll just have to absolutely nail unit 1 then.
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    (Original post by olivialloyd)
    Did you have to put the 12 part? I completely forgot to add that bit
    Maybe because theres other istopes of carbon like 16, but I don't know the mark scheme so maybe
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    (Original post by Nomes24)
    Ohhh right, don't worry, hopefully they won't want that much detail. I think I just put 3 proton, 4 neutron thing then the mass of a neutron and a proton is 1 each. Or maybe I did put relative atomic mass??! The brain trick thing is happening to me now xD
    Hopefully we both got the A* for Chemistry. I wish you the best for Physics!
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    (Original post by 11Jason11)
    Unofficial Grade Boundaries

    Chemistry Unit 2
    A*= 47
    A= 42
    B= 36
    C= 30
    D= 26

    Chemistry Unit 3
    A*= 45
    A= 39
    B= 32
    C= 26
    D= 21
    do you know the one for biology unit 2 and 3 aqua
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    did you guys find c3 difficult?
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    (Original post by iKali)
    did you guys find c3 difficult?
    I think the A* boundary will be aprox. 47 raw marks for C2 and for C3 it should be around 45 raw marks The exams were good but everyone is bound to make small silly mistakes even if all the knowledge is there , to prevent 100%
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    (Original post by iKali)
    did you guys find c3 difficult?


    i found unit 2 difficult i found unit 3 slightly easier
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    (Original post by kwstudent)
    Yep - Look for the post called C2 Paper GCSE - if u cant find it msg me and ill give u a link
    Could you send me the link please? :3
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    (Original post by Olivia197)
    Oh no- I thought it was asking about the backwards reaction because this produced the hydrogen iodide (can't remember what it was called) and so the yield of this would decrease because it is exothermic- how many marks would I lose?

    Raising the temperature would favor the forward reaction as endothermic draws in energy. This means more hydrogen and iodine will be produced from the thermal decomposition of hydorgen iodide.
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    http://www.thestudentroom.co.uk/show...1#post55816911 --OFFICIAL P2 & P3 THREAD
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    (Original post by Turtlebunny)
    Raising the temperature would favor the forward reaction as endothermic draws in energy. This means more hydrogen and iodine will be produced from the thermal decomposition of hydorgen iodide.
    No it was asking about the backwards reaction as the forwards reaction was endothermic
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    (Original post by thomasconnor)
    No it was asking about the backwards reaction as the forwards reaction was endothermic
    It asked whether increasing the temperature would have any affect on the amount of hydrogen iodide produced. They said the forward reaction was endothermic. Now read my answer, and you will see it is correct.
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    http://www.thestudentroom.co.uk/show...1#post55816911 --OFFICIAL P2 & P3 THREAD
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    so the grade boundaries will be quite low then. Do you guys have an unofficial mark scheme yet??
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    (Original post by Turtlebunny)
    It asked whether increasing the temperature would have any affect on the amount of hydrogen iodide produced. They said the forward reaction was endothermic. Now read my answer, and you will see it is correct.
    The reaction to produce hydrogen iodide was exothermic and so increasing the temp would decrease the yield mate
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    (Original post by Palette)
    Hopefully we both got the A* for Chemistry. I wish you the best for Physics!
    Thanks, you too!
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    (Original post by Turtlebunny)
    Raising the temperature would favor the forward reaction as endothermic draws in energy. This means more hydrogen and iodine will be produced from the thermal decomposition of hydorgen iodide.
    I agree with this. Increasing the temperature means they would try to decrease it by using an endothermic reaction (vs exothermic which would increase temperature further) and the endothermic reaction produced hydrogen and iodine, so more of the reactant- hydrogen iodide- would be used up.
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    (Original post by Theawesomejem)
    The reaction was exothermic?? also you had to talk about the affect of concentration on rate of reaction basically in relation to the table
    sorry yes, i meant exothermic
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    Does anyone have pics of the paper that they could send to me cause that would be great ! I think there was one student who had the paper but i can't remember the name . Thanks.
 
 
 
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