Chemistry II

posted by .

I cannot balance this equation and I am really struggling.

Cr2O7^2-(aq)+ Cu^+(s)-->Cr^3+(aq)+Cu^2+(aq)

How do I get the charges to balance?

  • Chemistry II -

    1. Place a 2 for Cr^+3. This is a temporary 2 and it may be changed later but you MUST start with the same number before counting electrons lost or gained or you will NEVER get it to balance.
    2. Now you count total charge on Cr in Cr2O7^-2 and that is +12. For Cr on the right we have 2Cr^+3 or +6 total. Therefore, Cr gained 6 electrons to go from +12 to +6 for the two Cr atoms.
    3. Cu is just one on each side. That is +1 on the left (but I DON'T think it is a solid) [or if it is then it is zero]. Assuming +1 on left and +2 on right is a loss of 1 electron.
    f. So you multiply the Cu^+1/Cu^+2 by 6 and the Cr2O7^-2/2Cr^+3 by 1 (which also means the temporary 2 for Cr^+ is now a permanent 2).
    4. Now you can add H^+ and H2O to balance the oxygen atoms and charges.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Chemistry

    Balance the following redox equations. All occur in Acidic solutions. 1. Cr2O7^2-^ + C2O4^2-^ -> Cr^3+^ + CO2 2. Cu + NO3^-^ -> CU^2+^ + NO 3. MnO2+ HNO2 -> Mn^2+^ + NO3^-^ 4. PbO2 + Mn^2+^ + SO4^2-^ -> PbSO4 + MnO4^-^ …
  2. chemistry

    Balance equation for reaction occuring in basic solution. CrO4{2-}+S{2-}gives S+CrO{-} i don't know how to balance the charges in this way of balancing please teach me how to do it?
  3. chemistry

    Fe2+(aq) + Cr2O7 2- (aq) →Fe3+(aq) + Cr3+(aq) Balance the equation by using oxidation and reduction half reactions. What is smallest possible integer coefficient of Cr3+ in the combined balanced equation?
  4. chemistry(balance equation)

    hi!i am a f4 student in hk.i have know the basic concept of balance equation.but some too complex equation i cant balance.is there any general short cut for balancing any simple or complex chemical equation?
  5. Chemistry

    Balance the redox equation by oxidation number method: Cr2O7 2- + Br- + H+ = Cr 3+ + Br + H2O Please help!
  6. Chemistry

    Complete and balance the following equation: Cr2O7{2-}(aq)+CH3OH(aq)-->HCO2H(aq)+Cr{3+}(aq) Any feedback would be great, thank you so much.
  7. Chemistry

    Complete and balance the following equation: NO2{-} + Cr2O7{2-} = Cr{3+} + NO3{-}
  8. Chemistry

    Complete and balance the following equation: NO2{-} + Cr2O7{2-} = Cr{3+} + NO3{-}
  9. chemistry

    Balance this chemical equation. Cr2O7 2-(aq) + Cu(s)---> Cr3+(aq) +Cu2+aq) I don't understand how to do this problem. Where do i begin?
  10. Chemistry

    Use the method of half reactions to balance the oxidation half reaction in acid solution as well as provide the oxidized and reduced reactants. Cr2O7 {2-} (aq) + F{-} (aq) = Cr {3+} (aq) + F2(aq) Charges are in { }

More Similar Questions