Given:
E⁰cathode = -0.76 V
E⁰anode = -0.91 V
To determine:
The equilibrium constant K for the reaction-
Cr(s) + Zn2+ (aq) ↔ Cr2+(aq) + Zn(s)
Explanation:
The relation between, E⁰cell and Keq is-
E⁰cell = (0.0592/n) log(Keq)
E⁰cell = E⁰cathode-E⁰anode = -0.76-(-0.91) = 0.15 V
n = # electrons in the reaction = 2
0.15 = (0.0592/2) * logKeq
logKeq = 5.07
Keq = 10⁵.⁰⁷ = 1.17*10⁵
Ans: the equilibrium constant is 1.17*10⁵