The pressure of H 2 required to make the potential of hydrogen electrode zero in pure water at 298 K is:

Step-by-step solution

P t , H 2 g H + Hydrogen electrode E H 2 / H + o = 0.0 V o l t H 2 g → 2 H a q + + 2 e - H + = 10 - 7 M at 25 o C (for Pure water) E = - 0.0591 2 log ⁡ H + 2 P H 2 E = 0 = log ⁡ H + P H 2 = 0 ∴ H + 2 = P H 2 = 10 − 7 2 ∴ P H 2 = 10 - 14 a t m