100. Solving a chemistry problem

3. For a concentration element composed of metal A in electrolyte solutions B with concentrations m1 and m2 mol / 1000 g, calculate the EMF at 298 K. Calculate the activity from the average activity coefficient taken from the reference book of physicochemical quantities, or (for dilute solutions ) by ionic strength. For a cell composed of a hydrogen electrode in an electrolyte solution C with a concentration of m3 mol / 1000 g and a calomel half-cell with a concentration of KCl m4 mol / 1000 g, calculate the EMF and pH of the solution containing electrolyte C. Do not take into account diffusion EMF. At 298 K the standard potential of the calomel electrode is 0.2812 V and the ion product of water is 1.008 x 10-14. Find the dissociation constants of weak electrolytes in the reference book of physical and chemical quantities.

Variant No. Substance m1 m2 С m3 m4 РН2, atm
A B
3 Ni NiSO4 0.1 0.7 HCOOH 0.3 0.03 0.50