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    (Original post by Anshul91)
    Al(H2O)6 3+ in excess OH is it Al(OH)4 - OR Al(OH)6 3- ???? THANKS
    [Al(OH)4(h20)2]-


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    (Original post by RoaringLion)
    [Al(OH)4(h20)2]-


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    PI thought the same but one markscheme says aloh6 3-
    pthough accept both
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    (Original post by Anshul91)
    Al(H2O)6 3+ in excess OH is it Al(OH)4 - OR Al(OH)6 3- ???? THANKS
    I've got [Al(OH)4]- colourless solution for xs OH

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    Wats the full equation for mno4- and c2o42-

    i got the half equations
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    (Original post by popnit)
    I've got [Al(OH)4]- colourless solution for xs OH

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    ah so whats the overall equation for excess naoh with aq aluminium please??
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    I can't sleep
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    (Original post by Anshul91)
    ah so whats the overall equation for excess naoh with aq aluminium please??
    Al(h20)6 3+ + 4OH- = al(oh)4- + 6h20
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    Do you only need to put state symbols when it asks for them ??
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    what times the exam?
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    (Original post by SexyAndIKnowIt.)
    Do you only need to put state symbols when it asks for them ??
    yeah if you put them and they're wrong and they didn't ask you get penalised


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    Good luck!!
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    (Original post by A sheesh)
    Lets just hope it's not a bull paper like June 12...
    that paper annoyed me so much, no matter what I did I got 0.1 for the gradient!



    also how is the ratio 3:5 can someone explain?
    well the deltaG scale was in kJmol^-1, if you converted it into Jmol^-1 you would get the gradient of 98-100 although they accepted 0.1 providing you put kJ K^-1 Mol^-1.

    The ratio one was where you had to recognise the FeC2O4 had two seperate partial equations that made up their half equation. Fe2+ --> Fe3+ + e- and C2042- --> 2CO2 + 2e- which combine to form the half equation Fe2+ + C2O42- --> Fe3+ + 2CO2 + 3e- (or FeC2O4 --> Fe3+ + 2CO2 + 3e-)

    the MnO4- was MnO4- + 8H+ + 5e- --> Mn2+ + 4H2O

    so when you combine the equations it becomes 3x the MnO4 reduction half equation and 5x the FeC2O4 oxidation half equation:

    3MnO4- + 24H+ + 5FeC2O4 --> 5Fe3+ + 10CO2 + 3Mn2+ 12H2O
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    Morning exam so 9am.

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    (Original post by Anshul91)
    what times the exam?
    Morning = 9am :cool:
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    (Original post by A sheesh)
    Wats the full equation for mno4- and c2o42-

    i got the half equations
    2MnO4- + 16H+ + 5C2O42- --> 2Mn2+ + 8H2O + 10CO2
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    Good luck everyone!!! xxx
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    why do transition metals show colour?
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    (Original post by Anjna)
    why do transition metals show colour?
    partially full d orbitals.
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    (Original post by Anjna)
    why do transition metals show colour?
    The exam is in an hour and a half. I know I'll get negged for this but how do you not know that?

    It's because the d orbital splits so light is absorbed when electrons are excited to the higher level
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    Well, here goes nothing


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