Kaya asked in Science & MathematicsChemistry · 2 months ago

can anyone teach me how to do redox (equations) step by step? i dont get any of it. 10th grade chemistry?

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  • 1 month ago

    guys please help me on my questions please 

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  • 2 months ago

    Some discussion and lots of solved examples:

    https://www.chemteam.info/Redox/Redox.html

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  • 2 months ago

    The Classic Example is iron(Fe) and potassium dichromate. in acidified solution.

    Taking the dichromate half equation first

    Cr2O7^2- Remember oxygen is always '-2' oxidation state.

    Hence"cr + 7(-2) = -2

    2Cr - 14 = -2

    2Cr = 12

    Cr = +6 (oxidation state) this is reduced to (+3)

    Hence Cr2O7^2- + 14H^+ 6e^- = 2Cr^3+ 7H2O

    Notice the Cr is now 2Cr^3+

    The 7 oxygens become 7 water

    We 'back' calculate the hydrogens from the water as '14'

    Then we balance the charges

    -2 + 14 -(x)e = 2(+3)

    -2 + 14 - xe^- = +6

    xe^- = +6 - 14 + 2 = -6

    So the 'x' of electrons is '6'

    So the half equation is

    Cr2O7^2- + 14H^+ 6e^- = 7H2O + 2Cr^3+ is the reductant side.

    This will oxidise Iron(II) to Iron)III)

    The half equation for iron is

    Fe^2+ = Fe^3+ + e^-

    We notice that there are 6 electrons in the dichromate half equation, so we need 6 e^- in the iron half equation.

    Hence 6Fe^2+ = 6Fe^3+ + 6e^-

    We now have two half equations viz.

    Cr2O7^2- + 14H^+ 6e^- = 7H2O + 2Cr^3+

    6Fe^2+ = 6Fe^3+ + 6e^-

    We now add the two half equations, this will eliminate the electrons (e^-)

    Cr2O7^2- + 14H^+ + 6Fe^2+ = 2Cr^3+ + 7H2O + 6Fe^3+

    Notice that the elements/atoms balance, and more particularly the charges balance, at '+26' on both sides.

    Hope that helps!!!!

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  • david
    Lv 7
    2 months ago

    If you want step-by-step  .. Try Kahn Academy .. an online teaching site.  It could be a very detailed set of instructions ... Give a google search for Kahn Academy and the lesson you need .. Redox Reactions 

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  • Anonymous
    2 months ago

    Since your Google must be broken I Googled it for you. Here’s a 4 minute video. Pay attention. 

    https://youtu.be/6gtcvqLmPo8

    Youtube thumbnail

    Source(s): I hope you fix your Google.
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