73. Solving a chemistry problem

31. The normal concentration of a KMnO4 solution in an acidic environment is 0.10 mol/l. Calculate the normality of this solution during titration:
1) in an alkaline environment with the formation of MnO2,
2) in an acidic medium in the presence of fluoride ions with the formation of the [MnF]2 complex
3) in an alkaline medium in the presence of BaCl2 with the formation of a BaMnO4 precipitate