2. The pH may be measured with a hydrogen electrode connected with a AgClAg electrode through a salt bridge. If the cell expression is Pt,H2(1bar)H+(aH+)::Cl(1m)AgClAg and the standard emf of AgClAg electrode is 0.22233 at 25C. (a) Write the half-eell reactions and cell reaction (3\%); (b) Derive the relationship between pH and E, ignoring the liquid junction potential (4\%); (c) Calculate the pH value when the emf of the cell is 0.520V at 25C.(3%)