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    only f325 jUNe in there. I need jan and june 09 and jan 10. MAJOR REPP FOR PERSON WHO UPLOADS
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    (Original post by blush.ox)
    Thats all i have, the june 2010 should be on the webiste me thinks
    thanks but i already have them and june 2010. I need june and jan 2009 and june 2010/
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    (Original post by tallysingh)
    thanks but i already have them and june 2010. I need june and jan 2009 and june 2010/
    for F325? theres no papers for that cus its a new spec, the rest for the other units are all on the website
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    (Original post by tallysingh)
    not f325
    F325 June 2010 is there - I've just had a look.

    Also, Ecstacy posted them on the first page of the thread - have a look there if noone else has uploaded them.
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    Singh, are you bonkers?! Rep isn't money you know.... Everyone on TSR seems to think they can almost bribe with "REP!" WTF....
    Oh wait... it's the currency of TSR...:doctor:
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    Biology F215 will be my worst nightmare... I quite enjoy chemistry!
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    (Original post by asem93)
    Singh, are you bonkers?! Rep isn't money you know.... Everyone on TSR seems to think they can almost bribe with "REP!" WTF....
    Oh wait... it's the currency of TSR...:doctor:
    Whats bribe. the website is about help. and i need help with finding past papers. So i guess the irony is on u mate
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    (Original post by tallysingh)
    Whats bribe. the website is about help. and i need help with finding past papers. So i guess the irony is on u mate
    You take the meaning literally... Okay... Speeks volume, and haven't you heard of sarcasm?
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    (Original post by asem93)
    You take the meaning literally... Okay... Speeks volume, and haven't you heard of sarcasm?
    loll okay i dont want no arguments, i just want past papers for jan and june 2009 and jan 2010.
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    (Original post by tallysingh)
    loll okay i dont want no arguments, i just want past papers for jan and june 2009 and jan 2010.
    Which papers in particular? As blush ox already mentioned, there are only three F325 papers: the Specimen paper, June 2010 and January 2011. The other papers are all on the OCR website.
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    (Original post by Salliana23)
    Which papers in particular? As blush ox already mentioned, there are only three F325 papers: the Specimen paper, June 2010 and January 2011. The other papers are all on the OCR website.
    so they are no new specifications papers for the Janaury, June 2009 series, and January 2010? I have the June 2010, Jan 2011 and Specimen papers already. Are there no past papers before June 2010, was june 2010 the first time you were able to take the F325 exam??
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    (Original post by tallysingh)
    so they are no new specifications papers for the Janaury, June 2009 series, and January 2010? I have the June 2010, Jan 2011 and Specimen papers already. Are there no past papers before June 2010, was june 2010 the first time you were able to take the F325 exam??
    No, not for this exam.
    Yep, June 2010 was the first sitting.
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    (Original post by Salliana23)
    Which papers in particular? As blush ox already mentioned, there are only three F325 papers: the Specimen paper, June 2010 and January 2011. The other papers are all on the OCR website.
    Thankyou for the back up :sigh: :rolleyes:.

    I've only just come across a half life Question on a Unifying concepts paper. I'd completely forgot about that area of the spec. Just noticed it hasnt been on the new spec papers, soo its likely to come up maybe .
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    (Original post by RyuHADOUKEN)
    No, not for this exam.
    Yep, June 2010 was the first sitting.
    thank you very much for clearing up confusion.
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    (Original post by Salliana23)
    Did you get the rate equation as rate = k[C2H4][O3]?

    As both of these reactants are in the overall equation, this means that the rate-determining step is the overall equation. That is why the rate that O2 is formed is the same as the initial rate, as the reaction only has one step.

    The rate has nothing to do with the number of moles.
    But the mark scheme doesn't agree with that either - it says that the rate has to divided by four
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    (Original post by Student21)
    Need some help on a question. Question is 2NO + O2 2NO2. Propose multi step reaction mechanism?

    Cant get my head round what to put in 2nd step. Thanks
    Can someone please help me, i still cant get my head round this question.

    2NO + O2 makes 2NO2. What the hell is the multi step reaction?

    K = [NO]2 so 2 molecules of NO in rate determining step yes?
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    (Original post by goldlock)
    But the mark scheme doesn't agree with that either - it says that the rate has to divided by four
    If you look at the table it's the rate of formation in respect to HCHO. Now look at the equation for the reaction and you'll notice that it's 2HCHO for every 1/2O2. That means that HCHO is formed 4 times as fast as O2 in the reaction. We have the rate of formation for HCHO, so to get the rate of formation of O2, we divide by 4. Hope that helps
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    (Original post by RyuHADOUKEN)
    If you look at the table it's the rate of formation in respect to HCHO. Now look at the equation for the reaction and you'll notice that it's 2HCHO for every 1/2O2. That means that HCHO is formed 4 times as fast as O2 in the reaction. We have the rate of formation for HCHO, so to get the rate of formation of O2, we divide by 4. Hope that helps
    :gasp: i get that now, thanks
    You have already rated a post by this user recently!
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    (Original post by goldlock)
    But the mark scheme doesn't agree with that either - it says that the rate has to divided by four
    Oh no sorry about that

    Edit - Maybe it's because the products are 2HCHO : 1/2 O2
    So the molar ratio is 4:1
    The initial rate is the initial rate of formation of HCHO not the rate of formation of all of the products (that's what I was getting confused about) so I think that's why the rate is divided by 4.

    I'll delete the other post - looked at the mark scheme for the first two parts of the question but I should have checked the rest!

    Edit 2 - Saw that Ryu Hadouken has already posted this
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    (Original post by Student21)
    Can someone please help me, i still cant get my head round this question.

    2NO + O2 makes 2NO2. What the hell is the multi step reaction?

    K = [NO]2 so 2 molecules of NO in rate determining step yes?
    yeah, whatever is in the rate equation is the rate determining step, so if rate=k[NO]2
    then 2NO features in slowest step
    i don't think you have to get it exact with regards to the multi step reactions, cus they're always 'suggest'
    but for this one i'd say

    2NO -> N2 + O2
    N2 + 2O2 ->2NO2 ?
    just as long as after cancelling out, it equals the original equation.
    and as long as it actually looks possible haha
 
 
 
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