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    (Original post by otrivine)
    hmm yes but you have to say via a connecting wire
    so you say that the two half cells are connected externally by a wire going to the pt electrode to another?
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    (Original post by Dr00n)
    so you say that the two half cells are connected externally by a wire going to the pt electrode to another?
    so the pt electrode is used in non metal and non metal ion half cells and also used between metal ion and metal ion, and the purpose of the pt electrode is to allow the transfer/movement of electron between the two half cells via a connecting wire

    my turn
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    has anyone done their qualitative on chromium compounds?
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    (Original post by otrivine)
    so the pt electrode is used in non metal and non metal ion half cells and also used between metal ion and metal ion, and the purpose of the pt electrode is to allow the transfer/movement of electron between the two half cells via a connecting wire

    my turn
    Define Polarisation
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    (Original post by Dr00n)
    Define Polarisation
    polarisation is the ability of an attraction between oppositely charged ions and there are 2 factors which affect polarisation and they are ionic size and charge denisty. The smaller the ion and greater charge density will result in a greater attraction between ions and hence, more exothermic because more energy is needed to break/separate the forces between ions.
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    (Original post by otrivine)
    polarisation is the ability of an attraction between oppositely charged ions and there are 2 factors which affect polarisation and they are ionic size and charge denisty. The smaller the ion and greater charge density will result in a greater attraction between ions and hence, more exothermic because more energy is needed to break/separate the forces between ions.
    yeah all good except the two factors are charge density and magnitude of charge i though?
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    (Original post by Dr00n)
    yeah all good except the two factors are charge density and magnitude of charge i though?
    No, its charge density and ionic size
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    (Original post by otrivine)
    No, its charge density and ionic size
    Ok yeah, my bad
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    (Original post by Dr00n)
    Ok yeah, my bad
    No worries!

    Define:enthalpy of hydration(2)
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    Could someone please help me in regards to the rate-determining step?
    Does it always have to be the first step in the mechanism of the reaction?

    eg. for 2NO2 + O2 = 2NO2
    rate = k[NO]2

    For the mechanism I put:
    O2 + N2 = N2O2
    N2O2 + 2NO = 2NO2 + N2

    But the answer is:
    2NO = N2O2
    N2O2 + O2 = NO2

    So does the slow step mechanism always happen first and is followed by the fast steps? I thought it didn't matter, so please someone tell me if I'm wrong!
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    Basically, the rate you are given i.e. k(NO)2 has to be the first step as it will be the slowest, or the rate determining step. So whatever it gives you in those brackets needs to be in your first step, and then the rest you can work out with the overall equation it gives you as well. Hope that helps!
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    Finally done Mod 2 phew, hopefully I can get the Questions done by the end of tonight, and start going through Mod 3 ASAP

    How far is everyone else?
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    (Original post by Wheeeto)
    Basically, the rate you are given i.e. k(NO)2 has to be the first step as it will be the slowest, or the rate determining step. So whatever it gives you in those brackets needs to be in your first step, and then the rest you can work out with the overall equation it gives you as well. Hope that helps!
    Oh right! Thank you!
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    has anyone got the complete mark scheme for the last couple of Qs of the June 2010 paper as the ocr website doesn't seem to give the answers to the last sections....

    It's ok I found it now!
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    (Original post by otrivine)
    No worries!

    Define:enthalpy of hydration(2)
    Can anyone help?

    Do we need to know the Standard Potential Values for Each Half-Cell in the Hydrogen-Oxygen Fuel Cell????????
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    F325 LEGACY PAPERS
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    Has anyone got the f325 jan 2013 paper? It would be such a great help for anyone to send me it
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    Please anyone:

    For Mod 2 does anyone know how to Balance REDOX Reactions where you have to add H+, OH- or H20.

    Really would appreciate help

    Any links would be great
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    (Original post by Better)
    Please anyone:

    For Mod 2 does anyone know how to Balance REDOX Reactions where you have to add H+, OH- or H20.

    Really would appreciate help

    Any links would be great
    hey how are you

    up for some revision
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    anyone want to revise transition
 
 
 
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