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Homework Help: Highschool chemistry redox

  1. Aug 27, 2007 #1
    im currently studying redox in chemistry and im really enjoying it so far.
    I am just a little bit confused about one section of it, that is that i cannot understand how to work out the product in the 1/2 equations ..

    e.g Fe2+ forms Fe3+.. but why does it form this.. i know iron is a reducing agent, and it gets oxidized and loses an electron.
    but other 1/2 equations confuse me, can anyone please explain this to me in simple chemistry terms that i can understand.. i would really appreciate it,

    thank you
  2. jcsd
  3. Aug 27, 2007 #2


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    one ion or material must act as a reducing agent to donate electrons and another material or ion must act as an "oxidizing" agent to accept electrons. The reducing agent goes through a half reaction and the oxidizing agent goes through the other half reaction.
  4. Oct 3, 2007 #3
    half ionic equations are just a simple breakdown of the actual redox reaction because redox involves two processes: oxidationa nd reduction. one species will be oxidised and the other will be reduced.

    you should kno the trends...i mean...like metals are reducing agents, metal ions are oxidising agents, halogens are oxidising agents, halide ions are reducing agents. then it'll be easier to identify which species will be reduced or oxidised. all this requires practice.

    for example iron has a max oxidation number of +3. so, Fe2+, will be oxidised to attain the highest oxidation state, i.e. Fe3+.

    but you will know al the redox products as you get along with your course.

    like managnate(VII) will be reduced to Manganese ion(Mn2+). or dichromate(VI) will be reduced to chromium (III) ion.

    there will also be exceptions also...like thiosulphate can be oxidised to sulphate ion by Cl2 or oxidised to tetrathionate ion by I2.

    this is not at all complicated....it'll be coming gradually....

    i'm doing my A level in chemistry and it is only recently that i understood that...i mean that i kno at a certain extent which products will be obtained,,,

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