Note 537 — Chapter XIV · OXIDATION AND REDUCTION REACTIONS. I
Reading edition
In a solution of zinc sulphate in which [Zn2+] = 0.114, the potential εZn, ZnSO4= −0.514 (the minus sign indicates that the metal named first in the subscript has a negative charge). Inserting the values for [Zn2+] and εZn, ZnSO4 in the general equation given on p. 261, and solving for K, we find K = 1017. For [Zn2+] = 0.022 and εZn, ZnSO4 = −0.535, we find K = 1016.8. (Cf. Wilsmore's tables, loc. cit.)