Explore BrainMass

Explore BrainMass

    Calculating the equilibrium constant

    Not what you're looking for? Search our solutions OR ask your own Custom question.

    This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

    Calculating the equilibrium constant. I have had trouble with this problem.

    The EXACT question asks: Calculate the equilibrium constant at 298K for the following equation.

    Sn(+2)(aq) + MnO4(-1)(aq) ===> Sn(+4)(aq) + Mn(+2)

    I understand Kc = (Products^(stoic. coefficients))/(Reactants^(stoic. coefficients))
    Stoic. coefficients = 1 (1:1)
    This is a no brainer, but how do I get a NUMERICAL Kc value?

    Perhaps I have to use thermodynamics (which I cannot find deltaG or deltaH for this equation), or perhaps Nernst equation using reduction potentials:

    MnO4(-1)(aq) + 8H(+)(aq) +5e ==> Mn(2+)(aq) + 4H2O 1.51v
    Sn(+4)(aq) + 2e ==> Sn(+2)(aq) 0.15v
    Balanced Eq:

    5Sn(+2) + 2MnO4(-1)+16H+ ==> 5Sn(+4)+2Mn(+2)+8H2O

    Or do I use an inverse : K(reverse) = 1/(K(forward)) but it is not a cell.
    Perhaps the rule of multiple equilibrium(adding reaction steps)
    I need a NUMERICAL answer, NOT just the Kc expression.

    If anyone can help me I would appreciate it immensely!

    © BrainMass Inc. brainmass.com March 4, 2021, 6:20 pm ad1c9bdddf

    Solution Preview

    Hi, you need to have some confidence in what you know on these.

    You know at equilibrium the cell emf is going to be zero so Eo is going to be 0.509/n log K
    It really does not matter if ...

    Solution Summary

    This solution is provided in 156 words. It uses equilibrium and Nernst relations to determine the equilibrium constant.