Chemistry

Using the standard reduction potentials, calculate the equilibrium constant for each of the following reactions at 298 K.

10Br- + 2MnO4- + 16H+ -> 2Mn2+ + 8H20 + 5Br2

Work:
2Br- -> Br2 + 2e- (This would be multiplied by 5 to balance out with the upper equation.)

MnO4- + 8H+ + 5e- -> Mn2+ +4H20 (This would be multiplied by 2 to balance out with the upper equation.)

The standard reduction potential for Br- is +1.065.

The standard reduction potential for MnO4- is +1.51.

  1. 👍 0
  2. 👎 0
  3. 👁 294
  1. Look up that equation, nEF = -lnK (I'm not at home and can't confirm that equation so check it out) but that is the one you want to use.

    1. 👍 0
    2. 👎 0
  2. I looked back through my notes and found the following equations:

    K = e^(-delta G/RT)
    Delta G = -nFE

    I know that E = standard reduction of the reduced - standard reduction of the oxidized

    I've tried plugging everything I have in, but I'm not getting the right answer. I can't figure out what it is that I am doing wrong.

    I have E = 1.51 - 1.065 and n = 10

    1. 👍 0
    2. 👎 0
  3. So I have that

    1.51 V - 1.065 V = .445 V = E

    and that

    ΔG = - 10 mol * 96485 J / mol*V * .445 V

    ΔG = -429358 J

    so then plugging in:

    K = e^(-(-429358)/(8.314 J/mol*K * 298 K))

    K = 1.82 * 10^75

    The 'correct' answer appears to be 1.5 * 10^75 , but that's not far off, and my homework program accepted my answer as correct.

    1. 👍 0
    2. 👎 0
    posted by Anon

Respond to this Question

First Name

Your Response

Similar Questions

  1. chemistry... HELP

    Equilibrium constant question!!!? Standard reduction potentials Reduction half-reaction E(V) Ag+(aq) + e- ---> Ag (s) 0.80 Cu ^2+ (aq) + 2e- ---> Cu (s) 0.34 Sn^4+(aq) + 4e- ---> Sn (s) 0.15 2 H+(aq) + 2e- ---> H2 (g) 0 Ni^2+(aq)

    asked by Ann on November 3, 2012
  2. Chemistry

    Using standard reduction potentials, show that one can prepare an ammine complex from CoCl2 and hydrogen peroxide in the presence of ammoinia but not in its absence. (need to write two redux reactions, calculate standard

    asked by Anonymous on April 26, 2012
  3. Chemistry

    use the appropriate standard reduction potentials in the appendix of your book to determine the equilibrium constant at 285 K for the following reaction under acidic conditions 4H+(aq) + MnO2(s)+2Fe+2(aq)----> Mn+2

    asked by Rachel on April 28, 2016
  4. chem

    Q: Calculate ℰ° values for the following cells. Which reactions are spontaneous as written (under standard conditions)? Balance the equations. Standard reduction potentials are found in the Standard Reduction Potentials table.

    asked by . on May 7, 2019
  5. Chemistry need help

    using standard potentials given in the appendices calculate the standard cell potentials and the equilibrium constants for the following reactions. Zn(s)+( Fe^2+(aq)) ---> (Zn^2+(aq))+ Fe(s) If anyone can show work, then I can do

    asked by Kader on April 19, 2014
  6. chemistry

    Calculate the equilibrium constant for 2CH3OH(l)+3O2(g)->2CO2(g)+4H2O(l) by using standard reduction potentials?

    asked by KAyla on May 18, 2011
  7. Chemistry- Please help!!

    Using standard reduction potentials, calculate the standard E¡Æcell, emf, for each of the following reactions. State if each reaction is spontaneous or nonspontaneous. (Use the below reactions AS WRITTEN, DO NOT REARRANGE ANY

    asked by Anna on April 16, 2011
  8. Chemistry

    Using standard reduction potentials, calculate the standard E¡Æcell, emf, for each of the following reactions. State if each reaction is spontaneous or nonspontaneous. (Use the below reactions AS WRITTEN, DO NOT REARRANGE ANY

    asked by Anna on April 16, 2011
  9. Chemistry

    Choose the two half-reactions from a table of standard reduction potentials that most closely approximate the reaction that occur within the battery. What is the standard voltage generated by a cell operating with these

    asked by Jay on May 7, 2011
  10. Chemistry-Plz see this DrBob

    I am sorry I do not know what happens the symbolism, so I just deleted the symbols. Is it works for you that deleted the symbols? Using standard reduction potentials, calculate the standard Ecell, emf, for each of the following

    asked by Anna on April 16, 2011

More Similar Questions