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    Hey guys I need help with oxidation numbers, if you could show how its done, it would be most appreciated.
    WO3 + 3H2 ----> W + 3H20
    Tungesten reaction with Hydrogen
    could you show whats being oxidised and reduced

    Also one more about sodium thiosulfate
    What is the oxidation number of sulphur in Na2 S2 O3 . 5H20 (Hydrated Sodium Thiosulfate)

    Look at your past notes and stuff if you can and online resources.

    All elements on their own are 0. If they're not ions, then they balance to = 0. Since 03 = -6, tungsten is = +6. It goes to 0. This means it has gained 6 electrons because -6 add +6 = 0. Use OIL RIG (oxidation is loss [of electrons], Reduction is gain [of electrons]). We can conclude that Tungsten has been reduced since it gained 6 electrons.
    3H2 = 0 because it's on its own. When in the water molecule, it's now at +1 (two Hydrogens will balance the -2 of the oxygen). This means it's lost an electron. This means it's been oxidised.

    I'm not sure about sulfur but I think since:
    Na = +1 and there's 2 of them = +2
    O3 = -6
    +2 + -6 = -4.
    How do we make -4 = 0? Well sulphur must be +2 since there's two of them.
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