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    Whats the equation for cobalt/ copper with excess oh-?
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    (Original post by Jmedi)
    They will tell you if it's in alkaline solution
    Thanks!
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    Help in my notes, the equation for [Cr(h20)6]3+ with EXCESS OH is [Cr(h20)3(oh)3] + 3OH- --> [Cr(oh)6]3- + 3h2o but this is the mark scheme help??! It's the same with excess nh3 too!!Name:  image.jpg
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    (Original post by Anam)
    [Al(h20)6]2+ + OH- ===> [Al(OH)4]- + 3h20

    is this equation right for excess oh- being added to aluminium
    Al(H2O)3(OH)3 + OH- ===> [Al(OH)4] - + 3H2O
    or
    [Al(H2O)6]3++ 4OH- ===> [Al(OH)4] - + 6H2O
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    (Original post by Chembio123)
    Help in my notes, the equation for [Cr(h20)6]3+ with EXCESS OH is [Cr(h20)3(oh)3] + 3OH- --> [Cr(oh)6]3- + 3h2o but this is the mark scheme help??! It's the same with excess nh3 too!!Name:  image.jpg
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    Can i see the question and I can see what's up
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    Hi,
    For the rechargeable & and non rechargeable cells do we need to learn the species involved in each or we would be given, if a question is asked on it ?
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    (Original post by Super199)
    Whats the equation for cobalt/ copper with excess oh-?
    i know u get cu(oh)2 and co(oh)2 which are both blue precipitates.

    only cobalt can be further oxidised at this point by air or h2o2 to give cr(h20)3(oh)3 which is brown ppte
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    (Original post by Chembio123)
    Help in my notes, the equation for [Cr(h20)6]3+ with EXCESS OH is [Cr(h20)3(oh)3] + 3OH- --> [Cr(oh)6]3- + 3h2o but this is the mark scheme help??! It's the same with excess nh3 too!!Name:  image.jpg
Views: 83
Size:  405.7 KB
    The question must ask for it to start with aq chromium
    Your equation is further substitution after the dilute OH- has been added
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    (Original post by Khadijahk)
    Hi,
    For the rechargeable & and non rechargeable cells do we need to learn the species involved in each or we would be given, if a question is asked on it ?
    The only cell half equations you need to know are the hydrogen fuel cell ones. All the others will be given if asked
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    Guys - if you would recommend I do any 3 CHEM5 papers, which ones would they be? Very short for time - hectic exam timetable
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    (Original post by SirRaza97)
    Al(H2O)3(OH)3 + OH- ===> [Al(OH)4] - + 3H2O
    What about if they ask for [Al(H20)6]2+ with excess OH?
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    What are the hydrogen fuel cell equations?
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    (Original post by Boundless_x)
    What about if they ask for [Al(H20)6]2+ with excess OH?
    [Al(H2O)6]3++ 4OH- ===> [Al(OH)4] - + 6H2O

    it's aliminium 3+ not 2+
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    (Original post by study2016)
    Guys - if you would recommend I do any 3 CHEM5 papers, which ones would they be? Very short for time - hectic exam timetable
    Any other than June 2015 i would say
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    What colour is
    [Cr(NH3)6]3+


    Posted from TSR Mobile
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    why topics from AS are you guys looking back at?
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    (Original post by Kikstar)
    Thank you so much! I can now sleep in peace haha. Best of luck in your exams


    Posted from TSR Mobile
    No worries! Good luck to you too
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    (Original post by Bloom77)
    What colour is
    [Cr(NH3)6]3+


    Posted from TSR Mobile
    Purple
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    Cobalt with excess OH-: [Co(H2O)6)2+ + 2OH- --> Co(H2O)4(OH)2 + 2H20
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    how do you suss out which species to use as the salt bridge of a cell
 
 
 
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