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    Hello please could someone explain to me why saying "The reaction of chloride ions with iron ions" is penalised here? I have no idea.

    Edit 1: The question is from CHEM5 June 2015.
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    (Original post by Super199)
    Can someone explain why with some of the complex with excess NH3 you get full substitution and some you don't

    Like cobalt gives [Co(NH3)6]2+ but copper doesn't for example
    Copper only forms 4 true ligands so only 4 NH3 can undergo ligand substitution
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    (Original post by GabrielSmith1998)
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    Hello please could someone explain to me why saying "The reaction of chloride ions with iron ions" is penalised here? I have no idea.

    Edit 1: The question is from CHEM5 June 2015.
    mate its basic AS chem 2 Ag+ reacts with Chloride ion to form Agcl, remember the salt bridge cant react with electrode or electrode solutions. Ive never seen a Fecl2 compound. Not sure though i haven't done the past paper yet.
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    (Original post by shiney101)
    Does anyone know the full equation for fe(h2o)4(oh)2 with oxygen to form fe(h20)3(oh)3?
    think its:

    4Fe(H2O)4(OH)2 + O2 --> 4Fe(H2O)3(OH)3 + 2H2O

    Half equations:

    Fe(H2O)4(OH)2 + OH- --> Fe(H2O)3(OH)3 + e- + H2O

    O2 + 4e- + 4H+ ---> 2H2O

    could be wrong though
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    (Original post by man i)
    mate its basic AS chem 2 Ag+ reacts with Chloride ion to form Agcl, remember the salt bridge cant react with electrode or electrode solutions. Ive never seen a Fecl2 compound. Not sure though i haven't done the past paper yet.
    Thanks for the quick reply, I am confused though because FeCl2 does exist I think. I just don't see why you get penalised for mentioning it, even if you have correctly mentioned the formation of AgCl.
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    http://filestore.aqa.org.uk/subjects...W-QP-JAN10.PDF

    Can someone explain 8c and what topic is it under?

    Why do we divide by 1/3 and I don't get the steps after
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    In conventional cell diagrams, I understand you add a comma between things which are the same state.
    What about between aq and l? Do you add a comma?
    Thank you


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    (Original post by Bloom77)
    In conventional cell diagrams, I understand you add a comma between things which are the same state.
    What about between aq and l? Do you add a comma?
    Thank you


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    itll only be l if its water. its not essential to include water in your representation, so i wouldnt worry about that
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    (Original post by ravichauhan11)
    think its:

    4Fe(H2O)4(OH)2 + O2 --> 4Fe(H2O)3(OH)3 + 2H2O

    Half equations:

    Fe(H2O)4(OH)2 + OH- --> Fe(H2O)3(OH)3 + e- + H2O

    O2 + 4e- + 4H+ ---> 2H2O

    could be wrong though
    There is no full equation as neither of the iron complexes react with excess OH- or NH3

    [Fe(H2O)6]3+ + 3OH- --> Fe(H2O)3(OH)3 + 3H2O
    [Fe(H2O)6]3+ + 3NH3 --> Fe(H2O)3(OH)3 + 3NH4+
    And that's it for Fe(III)

    For Fe (II)
    [Fe(H2O)6]2+ + 2OH- --> Fe(H2O)4(OH)2 + 2H2O
    [Fe(H2O)6]2+ + 2NH3 --> Fe(H2O)4(OH)2 + 2NH4+





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    (Original post by Super199)
    http://filestore.aqa.org.uk/subjects...W-QP-JAN10.PDF

    Can someone explain 8c and what topic is it under?

    Why do we divide by 1/3 and I don't get the steps after
    H3PO4 - It's a tri H+ acidid as I call them so each H3PO4 gives 3H+ but each NaOH is just 1 OH-
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    (Original post by zombaldia)
    H3PO4 - It's a tri H+ acidid as I call them so each H3PO4 gives 3H+ but each NaOH is just 1 OH-
    Write the equation between NaOH and P4O10, then balance.


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    (Original post by ravichauhan11)
    itll only be l if its water. its not essential to include water in your representation, so i wouldnt worry about that
    Thanks!
    Yes this was for water, but they included it in the January 2010 paper


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    Name:  Screen Shot 2016-06-21 at 16.22.54.png
Views: 51
Size:  13.6 KBcan someone explain this to me please ((((((((

    im desperate

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    (Original post by Bloom77)
    Write the equation between NaOH and P4O10, then balance.


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    Why are you quoting me?
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    (Original post by cuppycake3)
    Name:  Screen Shot 2016-06-21 at 16.22.54.png
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Size:  13.6 KBcan someone explain this to me please ((((((((

    im desperate

    Attachment 554323554327554300
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    for the equation you filp the more negative electrode and then combine the two equatio s (its like normally combining half equations where you must cancel out the electrons)
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    Can anyone help me

    1. How do you do those 5 mark calculations
    2 What half equations do we need to learn for them
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    because if you write it as the more positive electrode (fe) under the other (h)

    then apply the anti clockwise rule

    you get 2H+ + 2Fe3+ -> fe2+ + + H2

    what am i talking about someone help please
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    who else is absolutely bricking it for this exam lol.
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    Someone help please
    Why do you x2 for -348 and not 158?
    Question 1biii in June 2010 paper
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    Mark scheme: http://filestore.aqa.org.uk/subjects...W-MS-JUN10.PDF


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    (Original post by Ejsjwwj)
    for the equation you filp the more negative electrode and then combine the two equatio s (its like normally combining half equations where you must cancel out the electrons)

    is the more negative electrode the hydrogen one? how would i know?

    sorry I'm being so silly I'm just nervous thank you for your help
 
 
 
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