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    (Original post by Sakildo)
    Anyone know what the A* grade boundaries were on this paper during Jan 2010, June 2010 and Jan 2011? thanks.
    for jun 10 it was 82/100
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    (Original post by Ammy16)
    can someone please explain question 1 b iii from chapter 14 exam style qz in the nelson thornes book. Ive got the answer but don't quite get it.
    what is the answer?
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    (Original post by Ammy16)
    can someone please explain question 1 b iii from chapter 14 exam style qz in the nelson thornes book. Ive got the answer but don't quite get it.
    Treat each half of the cell as a reversible reaction
    So for the Fe one if you remove Fe 3+ then the system would oppose this by converting more Fe 2+ into Fe3+, this also produces more electrons which will decrease the electrode potential causing the overall emf of the cell to inrease.
    Hope that helps
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    (Original post by sam_xo)
    LOL But I can't remember them in order from the Periodic table I want to know the order off by heart, my teacher had this rhyme thing but I've completely forgotten it!
    ??? wot do u mean order?? they are already in order...
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    (Original post by Anon1993)
    You get a periodic table?!
    LOL Omg. I just realised I missed out half the point of this question!!!! Revision seriously is messing with my head. Woops :/ I meant the BONDING in the elements in order from Na to Cl. My teacher had this rhyme to help remember the bonding and structures but I can't remember it
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    (Original post by Mobs25)
    ??? wot do u mean order?? they are already in order...
    I missed out half the point of this question lol. I've just realised how dumb this sounds. I meant the BONDING in these elements. There's a rhyme to help remember but I forgotten it :/
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    i have this exam tomorrow, i'm screwed, bye bye lovely uni :erm:
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    In Jan 2011 paper, last question last marking point why did they do 1000/5 that's the only bit I don't get! Thanks.

    Edit:

    It's ok, got it. I need to remember to use my brain.
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    (Original post by kogaht)
    shouldnt more electrons increase the potential?
    Well electrons are negative so shouldnt more decrease it ?
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    What exactly do we need to know about rechargeable and no rechargeable batteries??
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    (Original post by strawberry_cake)
    Not too sure but I think someone said 82 earlier


    EDIT: yepp 82 for the jan10 and june10 papers
    Thank you!
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    Anyone else find the specimen paper a lot harder than the 3 real papers?
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    (Original post by NRican)
    What exactly do we need to know about rechargeable and no rechargeable batteries??
    Nothing apart from the equations for hydrogen fuel cells
    EDIT: and the social impacts so like that hydrogen is explosive making it difficult to implement yadda yadda
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    (Original post by Sparkly-Star)
    In Jan 2011 paper, last question last marking point why did they do 1000/5 that's the only bit I don't get! Thanks.

    Edit:

    It's ok, got it. I need to remember to use my brain.
    They are changing it to a concentration conc= moles/volume. The volume 5cm3 =needs to be in dm3. So they've converted that, which simplified multiplies the top by 1000. SOrry that might not make sense.

    Basically you have moles/5/1000 which is the same as moles*1000/5
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    (Original post by Raimu)
    Anyone else find the specimen paper a lot harder than the 3 real papers?
    Yeah it really is!
    It's usually like that though.
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    (Original post by kogaht)
    what is the answer?
    The answer is change in coc: decrease
    Explanation: equation moves to the right.
    Electrode potential decreases.
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    (Original post by a23m)
    Yeah they are like EDTA, its usually because in the reaction, you will for more particles on the product side than the reaction side, so there is an increase in entropy. So when you plug in this increase of entropy into the gibbs equation, "DELTA G" will be more negative.

    There is also something to do with equilibrium being very far to the product side, but what i said above is fine to get you the marks.
    ahh ok thanks for that, so you get more molecules on products cos the reaction might be for example

    [Cu(h20)6]2+ + [EDTA]4- ---> [Cu(EDTA)]2- + 6h20

    2 molecules goes to 7 molecules hence the increase the entropy...is that along what you were saying?
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    (Original post by sam_xo)
    LOL Omg. I just realised I missed out half the point of this question!!!! Revision seriously is messing with my head. Woops :/ I meant the BONDING in the elements in order from Na to Cl. My teacher had this rhyme to help remember the bonding and structures but I can't remember it
    Hahaha S'okay - i know the feeling
    but ionic, ionic, both, giant covalent, simple, simple. .
    Make up your own rhyme?
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    CHM5,
    Pleaseee be a decent paper;
    and have straight forward questions.
    Pleaseeeeeeeeeeeeeeee
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    (Original post by sam_xo)
    LOL Omg. I just realised I missed out half the point of this question!!!! Revision seriously is messing with my head. Woops :/ I meant the BONDING in the elements in order from Na to Cl. My teacher had this rhyme to help remember the bonding and structures but I can't remember it
    I think it maybe one of those things you just have to learn. Periodicity is immensely boring, theres not a lot of theory, just memory.

    I'd suggest remembering it as...
    ionic on the left of the periodic table (sodium and magnesium)
    and
    covalent on the right of the periodic table
    Aluminium is a funny one though, its a bit of both!
 
 
 
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