87.9 Electrode potential and electromotive forces 7.9.6 pH-dependence of Pourbaix diagram For electrode reaction with Ht or OH participating in, the electrode potential will depend on ph. 1.229 2H+2e—>H2 q=ge+0.05916la 0,401 =0.000-0.05916pH 0.000 H2 O,+4H++4e-)2H,o -0.828 q=p+0.05916lga =12290.05916pH 02468101214pH pH-potential diagram/Pourbaix diagram7.9.6 pH-dependence of  : Pourbaix diagram For electrode reaction with H+ or OH- participating in, the electrode potential will depend on pH. O2 + 4H+ + 4e - ⎯→ 2H2O  = ⊖ + 0.05916 lgaH + = 1.229 - 0.05916 pH  = ⊖ + 0.05916 lgaH + = 0.000 - 0.05916 pH 2H+ + 2e- ⎯→ H2 pH-potential diagram/Pourbaix diagram §7.9 Electrode potential and electromotive forces