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Chemistry redox

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    Name:  20161110_115013.jpg
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Size:  503.9 KBCan someone go through a couple of these, and show me how to go about one?
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    (Original post by Lucky10)
    Name:  20161110_115013.jpg
Views: 29
Size:  503.9 KBCan someone go through a couple of these, and show me how to go about one?
    Of course!
    Let us start with SO2
    Tell me what you know about the oxidation numbers of them already
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    (Original post by CheeseIsVeg)
    Of course!
    Let us start with SO2
    Tell me what you know about the oxidation numbers of them already
    S has a +2 charge and that oxygen has a -2 charge??
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    (Original post by Lucky10)
    S has a +2 charge and that oxygen has a -2 charge??
    Ok but remember with redox. If there are 2 non-metals, the most electronegative has te negative charge. Here this is oxygen, so it's oxidation number is -2.
    This is a compound so that means the overall charge has to be 0.

    So using this information. Sulphur must have a positive charge to counterbalance the 2 x (-2) (O2 = 2 times the -2 charge said above)
    So Sulphur must be ...?
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    (Original post by CheeseIsVeg)
    Ok but remember with redox. If there are 2 non-metals, the most electronegative has te negative charge. Here this is oxygen, so it's oxidation number is -2.
    This is a compound so that means the overall charge has to be 0.

    So using this information. Sulphur must have a positive charge to counterbalance the 2 x (-2) (O2 = 2 times the -2 charge said above)
    So Sulphur must be ...?
    +2??
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    (Original post by Lucky10)
    +2??
    No
    So as oxygen has an oxidation number of -2
    THere are 2 of them (-4)
    ANd 1 sulphur
    As the compound is neutral, it will have to balance out the -4 from the oxygen. so sulphur is +4

    Try another?
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    (Original post by CheeseIsVeg)
    No
    So as oxygen has an oxidation number of -2
    THere are 2 of them (-4)
    ANd 1 sulphur
    As the compound is neutral, it will have to balance out the -4 from the oxygen. so sulphur is +4
    Oh right thats helped and yeah it that's okay with you
    Try another?
    oh right, thats helped and yeah if thats fine by you
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    (Original post by Lucky10)
    oh right, thats helped and yeah if thats fine by you
    Yay :hugs:
    Do you mind posting one? on my phone and can't read the picture, sorry!
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    (Original post by CheeseIsVeg)
    Yay :hugs:
    Do you mind posting one? on my phone and can't read the picture, sorry!
    NaH
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    (Original post by Lucky10)
    NaH
    NaOH or NaH?
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    (Original post by CheeseIsVeg)
    NaOH or NaH?
    NaH please
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    (Original post by Lucky10)
    NaH please
    Ok. So we know sodium is a group one metal. What do you know about the group one metals?
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    Grp 1 is 1+, Grp 2 is 2+, Grp 3 is 3+, Grp 6 is 2-, Grp 7 is 1-, And u gotta know maybe ur standard ions such as (So4)2-, (PO4)3-, (NO3)-. (CO3)2-
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    (Original post by CheeseIsVeg)
    Ok. So we know sodium is a group one metal. What do you know about the group one metals?
    That it has 1 electron in its outer most shell
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    (Original post by OfficialChemist)
    Grp 1 is 1+, Grp 2 is 2+, Grp 3 is 3+, Grp 6 is 2-, Grp 7 is 1-, And u gotta know maybe ur standard ions such as (So4)2-, (PO4)3-, (NO3)-. (CO3)2-
    yeahh
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    (Original post by Lucky10)
    yeahh
    Would it be -1 as sodium has a charge of +1
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    (Original post by Lucky10)
    That it has 1 electron in its outer most shell
    So it would form an ion of +1, hence its oxidation state
    (Original post by Lucky10)
    Would it be -1 as sodium has a charge of +1
    H would be -1, yes
    Remember the overall charge of this is 0 so you can see H must be -1 is Na is +1
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    (Original post by CheeseIsVeg)
    So it would form an ion of +1, hence its oxidation state


    H would be -1, yes
    Remember the overall charge of this is 0 so you can see H must be -1 is Na is +1
    Can we do one where its a minus
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    MnO42-
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    (Original post by Lucky10)
    MnO42-
    Yep so, sorry was eating food!
    So we have an ion here.
    So whatever happens, we need the sum of the oxidation states to have a charge of -2

    We've spoken about Oxygen always being -2
    So here we have 4 oxygens, each with -2
    -2 times 4 = -8

    Now hold on

    We need an overall charge of -2
    The only other species we have here is Mn
    so its oxidation number must be ?
 
 
 
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