5. Solving a chemistry problem

14. At a height where the barometer shows 0.666 * 105 N / m2, a hydrogen electrode and a normal calomel electrode are used to determine the pH of a solution. For this solution at 298 K and pressure p=1.013*105 N/m2 pH is 4.0. What is the true pH of the solution given the actual hydrogen pressure at the same temperature?