Join TSR now and get all your revision questions answeredSign up now
    Offline

    0
    ReputationRep:
    Thank you so much!!
    Offline

    0
    ReputationRep:
    (Original post by Nstar184)
    Thank you so much!
    No worries! I'm just curious...are you resitting CHEM4 or is it revision for the EMPA/ISA?
    Offline

    0
    ReputationRep:
    (Original post by evan almighty)
    No worries! I'm just curious...are you resitting CHEM4 or is it revision for the EMPA/ISA?
    ISA revision..I couldn't find the mark scheme for the paper I did
    Offline

    2
    ReputationRep:
    Does anyone have a document they could attach of the colours of transition metal ion/complexes please?

    I find learning them so hard!!

    Posted from TSR Mobile
    Offline

    0
    ReputationRep:
    (Original post by Tullia)
    Attached.

    Credit to LogicGoat, as that is who posted them originally.
    Thank you both.
    Offline

    0
    ReputationRep:
    (Original post by Tullia)
    Attached.

    Credit to LogicGoat, as that is who posted them originally.
    Hello, pls can you help me with this question , I am a bit desperate!

    Please can you have a look at question 2c )
    http://papers.xtremepapers.com/AQA/C...W-MS-Jun02.pdf

    I don't really understand why it is -0.84 and not the positive value because I thought that the iron is oxidised. So 0.40+0.44 ---> 0.84 V
    How come it is positive value?
    • PS Helper
    Offline

    2
    ReputationRep:
    (Original post by Hart1995)
    Does anyone have a document they could attach of the colours of transition metal ion/complexes please?

    I find learning them so hard!!
    I've attached a couple of links that might help you out.
    Attached Images
      
    Offline

    0
    ReputationRep:
    (Original post by Tullia)
    I've attached a couple of links that might help you out.
    Hello pls can you help me with the question that I have asked too? Also, do we have to know about silicon tetrachloride for our spec? It appears often in the legacy papers!
    Offline

    2
    ReputationRep:
    (Original post by Tullia)
    I've attached a couple of links that might help you out.
    Thats great! Thanks a million!

    Posted from TSR Mobile
    Offline

    0
    ReputationRep:
    (Original post by Tullia)
    I've attached a couple of links that might help you out.
    Hello ,pls can you answer some of the questions that I have asked u?
    Offline

    3
    ReputationRep:
    (Original post by Hart1995)
    Does anyone have a document they could attach of the colours of transition metal ion/complexes please?

    I find learning them so hard!!

    Posted from TSR Mobile
    Here is another one
    Attached Images
     
    Offline

    1
    ReputationRep:
    Transition metal test tomorrow :eek3: I seem to be alright with the colours except for Cu which I just keep messing up :rolleyes: Hopefully I wont do too badly!
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by AmyLH)
    Transition metal test tomorrow :eek3: I seem to be alright with the colours except for Cu which I just keep messing up :rolleyes: Hopefully I wont do too badly!
    Aww I'm sure you'll do fine
    Offline

    1
    ReputationRep:
    Is it always the less positive electrode which has a greater tendency to oxidise?
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by Chris-69)
    Is it always the less positive electrode which has a greater tendency to oxidise?
    I thought the more negative electrode is always oxidised? I.e. Its an reducing agent so if thats what you mean by 'tendency to oxidise' then yes. Idk I might be wrong :L
    Offline

    1
    ReputationRep:
    (Original post by Sherlockedd)
    I thought the more negative electrode is always oxidised? I.e. Its an reducing agent so if thats what you mean by 'tendency to oxidise' then yes. Idk I might be wrong :L
    Yes, I said less positive which is essentially more negative :P . I say less positive as you could have one electrode with +0.14V and another as +0.9V etc. where by neither are negative.
    Offline

    0
    ReputationRep:
    (Original post by Chris-69)
    Yes, I said less positive which is essentially more negative :P . I say less positive as you could have one electrode with +0.14V and another as +0.9V etc. where by neither are negative.
    The lower electrode potential value (when compared to the standard hydrogen electrode) is oxidised and the one with the higher electrode potential value (again compared to the standard hydrogen electrode) would be reduced. Remember reduction always occurs at the cathode and you should be fine. The more reactive a metal is , the more it wants to be oxidised. Reaction going backwards, right? Makes sense now?
    Offline

    1
    ReputationRep:
    'oxidation of Cobalt 2+ by air in ammoniacal solution' can someone explain what this is please????
    • PS Helper
    Offline

    2
    ReputationRep:
    (Original post by JenniS)
    'oxidation of Cobalt 2+ by air in ammoniacal solution' can someone explain what this is please????
    [Co(H2O)6]2+ (aq) + 6 NH3 (aq) --> [Co(NH3)6]2+ (aq) + 6 H2O (l)

    4 [Co(NH3)6]2+ (aq) is unstable in the presence of oxygen, so Co2+ is oxidised to Co3+

    4 [Co(NH3)6]2+ (aq) + O2 (aq) + 4 H+ (aq) --> 4 [Co(NH3)6]3+ (aq) + 2 H2O (l)

    Does that help?
    Offline

    1
    ReputationRep:
    (Original post by Tullia)
    [Co(H2O)6]2+ (aq) + 6 NH3 (aq) --> [Co(NH3)6]2+ (aq) + 6 H2O (l)

    [Co(H2O)6]2+ (aq) is unstable in the presence of oxygen, so Co2+ is oxidised to Co3+

    4 [Co(NH3)6]2+ (aq) + O2 (aq) + 4 H+ (aq) --> 4 [Co(NH3)6]3+ (aq) + 2 H2O (l)

    Does that help?
    It does thanks! I knew those equations I just wasn't sure if they were the right ones for the questions, thank you!
 
 
 
Poll
Which pet is the best?

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Quick reply
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.