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CHEM1 15 May 2012 AQA OFFICIAL POST EXAM Watch

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    So how did everyone find it? I thought it went quite well

    For why X can be turned to Y, the reagent is H2, it was a hydrogenation reaction, i don't think you can write the name as it said formula
    That may have been a weird question as it isn't, i think, in the chem1 syllabus, its more GCSE and CHEM2
    the mole questions were quite OK, people may have found the first part of 5a) difficult
    you had to use PV=nRT and then mass=mole*Mr

    And the answer to the molecular formula question is B2Cl4

    But i wasn't entirely sure about the relative atomic mass question, did we have to make a formula in X and Y as a similar question has come up before.
    I did it by trial and error and got 86.4, i think? is that right?
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    (Original post by DisturbingKand0R)
    So how did everyone find it? I thought it went quite well

    For why X can be turned to Y, the reagent is H2, it was a hydrogenation reaction, i don't think you can write the name as it said formula
    That may have been a weird question as it isn't, i think, in the chem1 syllabus, its more GCSE and CHEM2
    the mole questions were quite OK, people may have found the first part of 5a) difficult
    you had to use PV=nRT and then mass=mole*Mr

    And the answer to the molecular formula question is B2Cl4

    But i wasn't entirely sure about the relative atomic mass question, did we have to make a formula in X and Y as a similar question has come up before.
    I did it by trial and error and got 86.4, i think? is that right?
    Got 86.4 aswell, but I can't see it being right as mine was just a complete guess of how to do it, be surprised if its right. For 5a) Pretty much got it all wrong but used the right method, found out moles using PV=nRT then found out mass using n x Mr but just seem to have different answer than everyone else, hopefully get 2/3 for method. Also, I put H2O for the reagent, any chance of getting the mark?
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    For the pv/nrt question did we not have to divide the number of moles by 5 before X by the RMM? All the info was for the total number of products and there were five so I thought we'd have to divide the answer from PV/RT by give to get one mole?
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    (Original post by lochbeau)
    Got 86.4 aswell, but I can't see it being right as mine was just a complete guess of how to do it, be surprised if its right. For 5a) Pretty much got it all wrong but used the right method, found out moles using PV=nRT then found out mass using n x Mr but just seem to have different answer than everyone else, hopefully get 2/3 for method. Also, I put H2O for the reagent, any chance of getting the mark?
    i think for the moles one, you would get 4/5 if all if the method was correct, and i'm pretty sure about 86.4, so it may have beeen a lucky guess. H2O?...mm.. i don't think so, because that means Y has to be a alcohol, it was just an alkane
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    (Original post by DisturbingKand0R)
    i think for the moles one, you would get 4/5 if all of the method was correct, and i'm pretty sure about 86.4, so you may have beeen a lucky guess. H2O?...mm.. i don't think so, because that means Y has to be a alcohol, it was just an alkane
    Got a good chance of an A if thats the case, think the PV = nRT question will make or break my grade. Either way, only got a C last time due to panic so even a B will suffice. If 86.4 is correct and my method is wrong, will I get all 3 marks, 2 or 1?
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    (Original post by lochbeau)
    Got a good chance of an A if thats the case, think the PV = nRT question will make or break my grade. Either way, only got a C last time due to panic so even a B will suffice. If 86.4 is correct and my method is wrong, will I get all 3 marks, 2 or 1?
    i think if the answer is right then you would get 1 mark, because all the other marks are method marks
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    (Original post by MediterraneanX)
    For the pv/nrt question did we not have to divide the number of moles by 5 before X by the RMM? All the info was for the total number of products and there were five so I thought we'd have to divide the answer from PV/RT by give to get one mole?
    we do divide, but i think by 3 not 5 as pv=nrt is only for gases, so you would only look at the moles of CO, it was the only gas product.
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    (Original post by DisturbingKand0R)
    i think if the answer is right then you would get 1 mark, because all the other marks are method marks
    Better than nothing I suppose, my method was to use 4 and 10, I THINK I done (85 + 10) x (87 + 4) and got 8640, divided by 100 to get 86.4. Something like that anyway, either really lucky or an unorthodox method.
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    Hmm I didn't know the equation question, the one with boron in question 5

    This was posted from The Student Room's Android App on my MT15i
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    (Original post by lochbeau)
    Better than nothing I suppose, my method was to use 4 and 10, I THINK I done (85 + 10) x (87 + 4) and got 8640, divided by 100 to get 86.4. Something like that anyway, either really lucky or an unorthodox method.
    Got the same as me.
    I tried it with 20 and 50 though. Got 86.4
    Tried it with another two sets of numbers, got 85.6 again.

    So, I think 85.6 is a safe bet.

    For the mass, did anyone get 2.18?
    Also, for the last Q, I got B2Cl7. =l
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    (Original post by lochbeau)
    Better than nothing I suppose, my method was to use 4 and 10, I THINK I done (85 + 10) x (87 + 4) and got 8640, divided by 100 to get 86.4. Something like that anyway, either really lucky or an unorthodox method.
    similar to my method then, i found that if you times 28.575 by 2.5 you get about 71 and both of these add to almost 100.
    therefore the percentage of the 85 one was 28.575% and the 87 one about 71%
    then i did (28.575*85)+(87*71) and divided it by 100....that gave me about 86.42.... and i gave it to one dp as 86.4

    A LONG TRIAL AND ERROR lol
    hope then answer is right if the method isn't
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    (Original post by Scienceisgood)
    Got the same as me.
    I tried it with 20 and 50 though. Got 86.4
    Tried it with another two sets of numbers, got 86.4 again.

    So, I think 86.4 is a safe bet.

    For the mass, did anyone get 2.18?
    Also, for the last Q, I got B2Cl7. =l
    last Q WAS B2Cl4
    i can't remember what i put for the mass one, but it looks right
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    I did: (85x2.5) + (87x1)
    divided all that by 3.5

    Got 85 something, I think..
    It felt right..
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    (Original post by Scienceisgood)
    Got the same as me.
    I tried it with 20 and 50 though. Got 86.4
    Tried it with another two sets of numbers, got 86.4 again.

    So, I think 86.4 is a safe bet.

    For the mass, did anyone get 2.18?
    Also, for the last Q, I got B2Cl7. =l
    Was B2Cl4 for definite I think, I think I done 35.5/86.3? and got 0.4, then done 10.8/13.7? and got 0.8, so 1:2 ratio, which would have meant empirical formula was BCl2, that was half of 163.6, so just doubled up and got B2Cl4. And let us hope 86.4 is right
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    (Original post by DisturbingKand0R)
    similar to my method then, i found that if you times 28.575 by 2.5 you get about 71 and both of these add to almost 100.
    therefore the percentage of the 85 one was 28.575% and the 87 one about 71%
    then i did (28.575*85)+(87*71) and divided it by 100....that gave me about 86.42.... and i gave it to one dp as 86.4

    A LONG TRIAL AND ERROR lol
    hope then answer is right if the method isn't
    I done the exact same at first! I was just putting numbers in my calculator and x's by 2.5 to try get 100%, didn't work out for me though, so used that method, thought it would be completely wrong but happy to see it wasn't.
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    (Original post by lochbeau)
    Was B2Cl4 for definite I think, I think I done 35.5/86.3? and got 0.4, then done 10.8/13.7? and got 0.8, so 1:2 ratio, which would have meant empirical formula was BCl2, that was half of 163.6, so just doubled up and got B2Cl4. And let us hope 86.4 is right
    yess, let us all pray 86.4 is right
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    i thought it went well, but I stupidly wrong b204 instead of cl4
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    Hey!!! I thogght it was an OKAY exam. . What did people get for the question why is the marcomolecular structure very good conductor or somthing? And suggest why titanium in different shapes have the same somthing??
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    Yes, and let us pray the last question is C2Cl7 =l
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    (Original post by AishaTara)
    i thought it went well, but I stupidly wrong b204 instead of cl4
    yeah i hate it when you know answer and write it wrong, happens to me all the time, hopefully not this time as i checked it for ages
 
 
 
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