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    ah

    NaBr + H2SO4 => NaHSO4 + HBr

    What happens here. What reduces what? Its worth 2M.
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    Is this redox? It looks to me that the H2SO4 is acting as an acid (proton donor) and the NaBr is acting as a base (proton acceptor)...
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    well, in h2so4 the hydrogenxygen ration is 2:4 to reduce something you decrease the ratio as is in the sodium hydrogen sulphate( ratio 1:4)
    I think that's right and I hope it helps!
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    my teacher said Br2 is formed and consequently brown fumes are formed.
    but she never told us which reduced which, to allow this to happen..

    People any answers???
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    2HBr +H2SO4 --> Br2 + SO2 + 2H2O
    AQA CHEM2?
    Got it tomorrow too :sigh:
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    (Original post by Smeh)
    2HBr +H2SO4 --> Br2 + SO2 + 2H2O
    AQA CHEM2?
    Got it tomorrow too :sigh:
    CCEA.

    Ah do you know which reduces which?
    it doesn't ask for equation.
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    look in the AQA chem book if you have one on pg170/171

    anyway from what i have understood (from revising this all day), is that this is an acid / base reaction (so no reduction or oxidation happening here)- notice that the oxidation state of each element stays the same i.e. Na+1 before and same afterward, H+1 b4 and after.,etc..only H+ ions are moved from one species to another which makes it acid/base..(this much should get you your marks)

    extra info:
    now the Br- goes on to reduce HBr further to make Br2 the bromide ions (Br-) are stronger reducing agents than chlorine ions hence they reduce the sulfuric acid to sulfur dioxide..that must be what your teacher told you..
    the reaction is :

    2 HBr + H2SO4 = SO2 + 2H2O + Br2

    here, the Br is oxidised from -1 to 0. and the S is reduced from +6 to +4 hence this is a redox reaction.

    i am not too good at describing things..anyway i tried
    hope this helped
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    (Original post by ddxxx)
    look in the AQA chem book if you have one on pg170/171

    anyway from what i have understood (from revising this all day), is that this is the first step..and is an acid / base reaction - notice that the oxidation state of each element stays the same i.e. Na+1 before and same afterward, H+1 b4 and after.,etc..only H+ ions are moved from one species to another which makes it acid/base..

    now the Br- ( which is a stronger reducing agent that Cl) goes on to reduce HBr further to make Br2..that must be what your teacher told you..
    the reaction is :

    2 HBr + H2SO4 = SO2 + 2H2O + Br2

    here, the Br is oxidised from -1 to 0. and the S is reduced from +6 to +4 hence this is a redox reaction.

    i am not too good at describing things..anyway i tried
    hope this helped
    Ultimately Br- reduces HBr to Br2?

    Thanks so much for helping. Good luck tomorrow.xx
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    the h2so4 is the thing that's being reduced
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    (Original post by MedAmy)
    Ultimately Br- reduces HBr to Br2?
    I meant Br- in HBr is oxidised to Br2 ( Oxidation state of Br goes from -1 in HBr to 0 in Br2)..if that helps

    i saw what confused you..i edited my original post
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    H+ +e- ----> 1/2H2

    half eqn for typical reaction of acid, it tends to form H2 in most of these redox reactions, but could also form water, and some other stuff in certain cases.

    It gains electrons, so it has been reduced. The eqn you show was only half way through, the Br- will eventually get oxidised to Br2, and giving off SO2 gas for a thermodynamically favourable process.
 
 
 
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