119. Solving a chemistry problem

Coulometric titration of an aliquot of the analyzed solution of potassium permanganate with a volume of V(KMn04) was carried out with electrogenerated iron(II) in a sulfuric acid medium at a constant current i in the presence of ferroin indicator. An iron(III) salt was used as an auxiliary reagent. The current was passed for time τ until the color of the solution changed.
Write the equations for the reactions that take place during the titration on the generator electrode and in the solution. Using the data below, calculate the molar concentration c(l/z KMn04 equivalent) and the molar concentration c(KMnO4) of potassium permanganate in the analyzed solution.
V(KMnO4), ml i, mA τ
4.00 50 6 min 26 s