Calculate the standard potential, e∘, for this reaction from its equilibrium constant at 298 k. x (s) + y4 + (aq) ↽--⇀x4 + (aq) + y (s) k=4.98*10-5

First, we need to get the number of moles:

from the reaction equation when Y4 + takes 4 electrons and became Y, X loses 4 electrons and became X4+

∴ the number of moles n = 4

we are going to use this formula:

㏑K = n * F * E/RT

when K is the equilibrium constant = 4.98 x 10^-5

and F is Faraday's constant = 96500

and the constant R = 8.314

and T is the temperature in Kelvin = 298 K

and n is number of moles of electrons = 4

so, by substitution:

㏑4.98 x 10^-5 = 4*96500*E / 8.314*298

∴E = - 0.064 V