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    you know for non-rechargable battery cells..
    do wejust need to know the half equations andhow to write the cell emf?
    what about the electrolyte used for it?
    or do we need to know everything for each type like the advantages and disadvantages aswell?
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    ummm

    9 You are required to plan an experiment to determine the percentage by mass of sulphate ions
    in some solid waste made up of the three compounds silicon dioxide, sodium carbonate and
    magnesium sulphate.
    You are provided with dilute hydrochloric acid, a solution of barium chloride and simple
    laboratory equipment. (Hydrochloric acid reacts with carbonate ions and prevents the
    precipitation of barium and magnesium carbonates.)
    (a) Outline how you would extract the sulphate ions from the solid waste and convert the
    extracted sulphate ions into a precipitate of barium

    Do we need to know how to answer this q? Its in the june03 paper and I have no idea
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    (Original post by BethBeth)
    No probs, hope your revision is going okay!
    Have you done question 7 b ii) ?

    infact nevermind i got it
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    (Original post by strawberry_cake)
    ummm

    9 You are required to plan an experiment to determine the percentage by mass of sulphate ions
    in some solid waste made up of the three compounds silicon dioxide, sodium carbonate and
    magnesium sulphate.
    You are provided with dilute hydrochloric acid, a solution of barium chloride and simple
    laboratory equipment. (Hydrochloric acid reacts with carbonate ions and prevents the
    precipitation of barium and magnesium carbonates.)
    (a) Outline how you would extract the sulphate ions from the solid waste and convert the
    extracted sulphate ions into a precipitate of barium

    Do we need to know how to answer this q? Its in the june03 paper and I have no idea
    June 03 is from the old spec so I really doubt this will come up
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    do we need to know about adsorption and desorption of homogeneous catalysts?
    it doesn't say anything about it specifically in the spec and it isn't in the textbook as far as i can see but it has been on a few practice questions i've done
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    (Original post by clairecourtney)
    do we need to know about adsorption and desorption of homogeneous catalysts?
    it doesn't say anything about it specifically in the spec and it isn't in the textbook as far as i can see but it has been on a few practice questions i've done
    It's from unit 2, so I'd just briefly go over it.
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    Why are there 2 MNO4- in the overall equation for autocatalysis?
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    (Original post by InItToWinItGetIt?)
    Why are there 2 MNO4- in the overall equation for autocatalysis?
    In the MnO4- equation there are 5 electrons and in the C204 2- there are 2 electrons, you want the same number of electrons so you times the MnO4- one by 2 to get 10 electrons, this means everything has to multiplied by 2 so there is 2 MnO4-
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    (Original post by clairecourtney)
    do we need to know about adsorption and desorption of homogeneous catalysts?
    it doesn't say anything about it specifically in the spec and it isn't in the textbook as far as i can see but it has been on a few practice questions i've done
    Adsorption only happens on heterogeneous catalysts, where reactants are adsorbed usually by a metal catalyst, react and then are released...

    Homogeneous catalysts are in the same phase as reactants (usually aqueous) so surely they can't be adsorbed?

    (Correct me if I'm wrong people).
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    Does anyone have a list of the acid-base reactions:
    like Na2O + P4O10 .. etc

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    is there a possibility of M=QC/\T coming up? (from unit 2)
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    (Original post by teddyWS)
    is there a possibility of M=QC/\T coming up? (from unit 2)
    Q=mcdT.

    It can come up
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    (Original post by Arab_Empress)
    Does anyone have a list of the acid-base reactions:
    like Na2O + P4O10 .. etc

    At the bottom

    http://www.a-levelchemistry.co.uk/AQ...ary%20home.htm
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    (Original post by starburst92)
    June 03 is from the old spec so I really doubt this will come up
    ohh okies, thanks
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    yep but got to remember to get Q you have to do
    deltaH x number of moles
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    how do you work out h from q=mct
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    so much to do
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    hey in thermodynamics ive read that smaller ions lead to bigger lattice formation enthalpies due to the charges being closer together etc, but ive also read that with bigger anions you get larger enthalpies due to being distorted by the cation and hence there is slight convalence.

    does anyone know which is correct ?
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    So many equations to remember!
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    Also what leads to strong ionic bonding?
    small ions?
 
 
 
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