22. Solving a chemistry problem

13. To determine manganese in steel using the additive method, a sample of m steel was dissolved in a mixture of acids and, after separating interfering ions, the solution was diluted to 200.0 ml. An aliquot of 20.00 ml was placed in the electrolyzer and the polarographic wave height h1 was measured at E = -1.55 V. After adding a standard solution of 0.05 M MnSO4 to the electrolyzer Vst, the wave height became equal to h2 Calculate the mass fraction of manganese in the sample:
Option 13
m,g 1.6500
h1, mm 22.5
Vst, ml 5
h2, mm 35.0