Question

A voltaic cell is constructed in which the cathode is a standard hydrogen electrode and the anode is a hydrogen electrode ()= 1atm) immersed in a solution of unknown [H+]. If the cell potential is 0.190 V, what is the pH of the unknown solution at 298 K? pH =

Answer 1

Answer 2

The pH of the unknown solution can be calculated using the Nernst equation: E = E₀ - (RT/nF) * ln([H⁺]/[H₂]) where E₀ is the standard hydrogen electrode potential [1], R is the gas constant, T is the temperature (in Kelvin), n is the number of electrons transferred, and F is the Faraday constant. Plugging in the given values, we get: E = 0.190 V = 0.0000 - (8.314 J/mol K * 298 K / 1 mol) * ln([H⁺]/1) Solving for [H⁺], we get [H⁺] = 0.001879 mol/L, and the corresponding pH is 2.735.