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    2NaOH + Cl2 ----> NaCl + NaOCl + H2O Clearly identify the chemical species that are oxidised and those that are reduced and write oxidation and reduction half reactions.

    I know chlorine is both oxidized and reduced but could someone help me with the half reactions please?
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    "Undergraduate"
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    Cl2 -> Cl-

    AND

    Cl2 -> ClO-

    You surely can do the rest.
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    (Original post by alow)
    "Undergraduate"
    I fell your pain. I wouldn't have know which side of the under/post-graduate divide this would fall, either.
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    Cl2 + 2e- --> 2Cl-

    Cl2 + 2e- --> 2ClO- where do you get the O to balance this?
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    From water.

    Which will also mean adding H+ ions.

    Which might make you change your mind about the e-.
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    (Original post by Pigster)
    From water.

    Which will also mean adding H+ ions.

    Which might make you change your mind about the e-.
    Is the first one correct?

    Cl2 + 2OH- --> 2ClO- + 2e- + 2H+
    That isn't right is it?
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    You can't have OH- on the left and H+ on the right.

    The O in ClO- comes from water, not OH-.
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    (Original post by Pigster)
    You can't have OH- on the left and H+ on the right.

    The O in ClO- comes from water, not OH-.
    I don't understand. Will you show me how to write them correctly?
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    Cl2 -> ClO-

    Cl2 -> 2ClO-

    Cl2 + 2H2O -> 2ClO-

    Cl2 + 2H2O -> 2ClO- + 4H+

    Cl2 + 2H2O -> 2ClO- + 4H+ + 2e-
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    (Original post by Pigster)
    Cl2 -> ClO-

    Cl2 -> 2ClO-

    Cl2 + 2H2O -> 2ClO-

    Cl2 + 2H2O -> 2ClO- + 4H+

    Cl2 + 2H2O -> 2ClO- + 4H+ + 2e-
    Thank you!

    H2O + Cl2 --> HCl + HOCl
    Would these be the right half reactions for this reaction?

    Cl2 + 2H+ + 2e- --> 2HCl

    Cl2 + 2H2O --> 2HOCl + 2H+ +2e-
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    You wouldn't usually show them as acids in the half equation as they should be ionic equations, and the H+ on both sides would cancel.
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    (Original post by Pigster)
    You wouldn't usually show them as acids in the half equation as they should be ionic equations, and the H+ on both sides would cancel.
    How would you write them?
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    You've already done the Cl- one yourself, I have already done the ClO- one.
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    Cl2 + 2e- --> 2Cl-

    Cl2 + 2H2O --> 2OCl + 4H+ + 2e-

    Are these the correct ionic equations?
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    Apart from the charge missing, they look fine.
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    (Original post by Pigster)
    Apart from the charge missing, they look fine.
    Thanks! Last one.

    F2 + 2KBr --> Br2 + 2KF

    F2 + 2e- --> 2F-
    2Br- --> Br2 + 2e-

    That's it right?
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    Agreed.
 
 
 
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