Calculate the standard cell potential (E?) for the reaction X(s)+Y+(aq)→X+(aq)+Y(s) if K = 1.85×10−3.

 

As K<1, the reaction is not spontaneous.

Now at equilibrium, ?G° = - RT lnK, where R is the gas constant, T is the temperature.

Also, ?G° = -nFE°

Combining these two equations, we have, E°= RT/nF *lnK

E°= (8.314472*298.15/1*96485)*ln(1.85*10^-3)

E°= 0.02569*(-3*ln10 +ln1.85)

E°= 0.02569*(-6.9077 + 0.6151)

E°= -0.1616V