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Electro chem help please

  1. Jun 2, 2009 #1
    1. The problem statement, all variables and given/known data
    Refer to the cell below:
    Pt / MnO4-(0.10 M), Mn2+(0.20 M).H+(0.010M) // Cr3+(0.40 M), Cr2O72-(0.30 M), H+(0.010M) / Pt
    The standard reduction potentials are as follows:
    MnO4- + 8H+ + 5e- --> Mn2+ + 4H2O; E° = 1.51 V
    Cr2O72- + 14 H+ + 6e- --> 2 Cr3+ + 7H2O; E° = 1.33 V
    What is the value of the equilibrium constant at 25°C for the net spontaneous cell reaction?

    a. 7.3 x 10^-11

    b. 6.1 x 10^-92

    c. 91

    d. 1.1 x 10^3

    e. 2.1 x 10^91

    any help would br greatful appreciated. thanks
  2. jcsd
  3. Jun 3, 2009 #2


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