To determine the Tafel slopes for the oxidation of H2 gas and the reduction of O2 gas, we need to consider the Tafel equation: = b * log i / i0 where is the overpotential, b is the Tafel slope, i is the current density, and i0 is the exchange current density.For the oxidation of H2 gas anode reaction :H2 2H+ + 2e-For the reduction of O2 gas cathode reaction :O2 + 4H+ + 4e- 2H2OThe Tafel slopes b can be determined from the Butler-Volmer equation, which relates the current density to the overpotential:i = i0 * exp a * F * / R / T - exp -c * F * / R / T where a and c are the anodic and cathodic transfer coefficients, F is the Faraday constant 96485 C/mol , R is the gas constant 8.314 J/mol K , and T is the temperature in Kelvin.For the H2 oxidation and O2 reduction reactions, the transfer coefficients are typically a = c = 0.5. Assuming a temperature of 298 K 25C , we can calculate the Tafel slopes as follows:b = 2.303 * R * T / * F For the oxidation of H2 gas anode :b_anode = 2.303 * 8.314 J/mol K * 298 K / 0.5 * 96485 C/mol 0.120 V/decadeFor the reduction of O2 gas cathode :b_cathode = 2.303 * 8.314 J/mol K * 298 K / 0.5 * 96485 C/mol 0.120 V/decadeThe Tafel slopes for both the oxidation of H2 gas and the reduction of O2 gas using a platinum electrode in a 1 M acidic solution are approximately 0.120 V/decade.