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Size:  82.7 KB I wrote the answer in the markscheme but I don't know how they got it


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    Basically: one half equation + other half equation = full equation

    [NiO(OH) + H2O + e- ---> Ni(OH)2 + OH-]
    +[half equation you need]
    --------------------------------------------------------------
    [MH + NiO(OH) ---> M + Ni(OH)2]

    So anything that is on the left of the full equation but not in the given half equation => you need on your left (MH)

    Anything on the left of the half equation that isn't on the left of the full equation => you need on your right (H2O + e-)
    Other way around with your right hand side...

    Anything that is on the right of the full equation but not in the given half equation => you need on your right (M)

    Anything on the right of the half equation that isn't on the right of the full equation => you need on your left (OH-)
    Put it all together: MH + OH- ---> M + H2O + e-

    Just check that the species and charges balance It gets quicker with practice :yep:
 
 
 
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