1. Questions

Chemistry

Okay, so i've got 8 reactions i am supposed to balance "according to the half-reaction method". Only problem is, i was gone for the lesson, and my borrowed notes look like an entirely different language!
So if you could please show me the steps and explain how to do the first one, that would be MOST appreciated!

Fe+2 + MnO4- ====> Fe+3 + Mn+2

Thank you SO very much!

  1. 👍
  2. 👎
  3. 👁
Nessy

  1. The half reaction method I use is not standard but I use it because it uses the oxidation states and it was a way for me to make sure students knew oxidation states and how to determine them.
    1. Divide the reaction into half reactions
    Fe^+2 ==> Fe^+3
    MnO4^- ==> Mn^+2

    2. Determine the oxidation state. I will do Mn first.
    Mn is +7 on the left, +2 on the right.

    3. Add electrons to the appropriate side to balance the change of oxidation state.
    MnO4^- + 5e ==> Mn^+2
    (Note:+7 +5e = +2--not the charge of +2 but the oxidation state of +2).

    4. Now count the charge on the left and right. I see -6 on the left; +2 on the right. and
    a. If acid solution, add H^+ to balance the charge.
    b. If basic solution, add OH^- to balance the charge.
    This is acid so we add H^+ to balance the charge which means add 8H^+ to the left.
    MnO4^- + 5e + 8H^+ ==> Mn^+2
    (I always check it to make sure; I see +2 on the left and right).

    5. Now add water to balance the H^+ which means 4H2O.
    MnO4^- + 5e + 8H^+ ==> Mn^+2 + 4H2O

    6. Balance the other half using the same method. In this case, it is just one step.
    Fe^+2 ==> Fe^+3 + e

    7.Multiply each equation by a coefficient to make the electron change the same; i.e., multiply the Mn equation by 1 and the Fe equation by 5 and add them.
    5Fe^+2 + MnO4^- + 8H^+ + 5e ==> Mn^+2 + 4H2O + 5Fe^+3 + 5e.

    8. Cancel anything common to both sides; in this case, cancel the 5e, then check to make sure it balances three ways.
    a. the atoms must balance.
    b. the charge must balance.
    c. the changer of electrons must balance.
    Done.

    1. 👍
    2. 👎
    DrBob222

Respond to this Question

First Name

Your Response

Similar Questions

  1. chemistry

    MnO4–(aq) + Cl–(aq) Mn2+ + Cl2(g) (unbalanced) i. Write the reduction and oxidation half-reactions (without electrons). (.5 point) ii. Balance the equations for atoms (except O and H). (.5 point) iii. Balance the equations for

  2. chemistry

    2. What is the reduction half-reaction for the following unbalanced redox equation? Cr2O72– + NH4+ Cr2O3 + N2 A.) Cr2O3 -> Cr2O7^2– *B.) Cr2O72– -> Cr2O3 C.) NH4+ -> N2 D.) N2 -> NH4+ 3. Which oxidation-reduction reactions

  3. Chemistry

    Balance the following chemical equation using the half reaction method in acidic conditions: I2 + ClO3- → IO3- + Cl-

  4. chemistry

    Balance the following redox equation occurring in a basic solution: AG + CN{-} + O2 = AG(CN)2{-} I tried...but this is wrong...2H2O+ AG + CN{-} + O2 = AG(CN)2{-}+4OH{-}... I am supposed to do half reactions...how do I spit the

  1. Chemistry

    Please write down the redox reactions (using the half-reaction method!) a)Cl2 from OCl- and Cl- in acidic solution b)Br2 from BrO3- and Br- in acidic solution -You don't have to do both, but could you help me step up the half

  2. chemistry

    Use the following pair of reduction half-reactions to design a galvanic cell. Then write in the proper coefficient for each of the species involved in the overall reaction. Water molecules and protons are not shown in the

  3. Chem, Oxidation

    Complete and balance the following half-reactions. In each case indicate whether the half-reaction is an oxidation or reduction. (Use the lowest possible coefficients. Include states-of-matter under SATP conditions in your

  4. Chemistry

    Balance these reactions using the half-reaction method Sn2+ + IO3- -> Sn4= + I- (acidic solution) CrO2 + ClO- -> CrO42- + Cl- (basic solution)

  1. Chemistry

    Dr.Bobb222 please help balance the following oxidation-reduction reactions, which occur in acidic solution, using the half-reaction method. (Use the lowest possible coefficients. Include states-of-matter under the given conditions

  2. chemistry- redox

    Complete and balance the following equations using the method of half-reaction. both reactions happen in acidic solutions: a. Cu(s) + NO3-(aq)--> Cu2+(aq) + NO2(aq) b. Mn2+(aQ) + NaBiO3(s)--> Bi3+(aq) + MnO4-(aq) I'm having

  3. Chemistry

    Balance the following redox reaction occurring in an acidic solution: ClO4^-+Br2=Cl^-+BrO3^- I get the two half reactions balanced as: 6e^-+(8H^+)+ClO4^-=Cl^-+4H2O and 6H2O+Br2=2BrO3^-+(12H^+)+10e^- Then I multiply the top

  4. Chemistry

    3. Which oxidation-reduction reactions are best balanced by the half-reaction method? A.) covalent reactions *B.)acid-base reactions C.) ionic reactions D.) intermolecular reactions Thank you.

You can view more similar questions or ask a new question.