70. Solving a chemistry problem

At a temperature of 291 K, the EMF of the galvanic circuit, composed of quinhydrone and calomel electrodes, is 0.142 V. At 291 K, the potential of the calomel electrode is 0.25 V, and that of the quinhydrone is (0.704 0.058 lg aN). Determine the pH of the solution and the concentration of hydrogen ions. Make a galvanic circuit.