26. Solving a chemistry problem

To determine the titer of potassium permanganate for chromium, 1.00 g of steel containing 2.12% chromium was taken. Steel shavings were dissolved in a mixture of acids, chromium was oxidized with ammonium persulfate, and heated until the evolution of gas ceased. After heating, 25.00 ml of Mohr´s salt solution ((NH4)2SO4*FeSO4*6H2O) was added. The excess of this salt was titrated with a solution of potassium permanganate, using 10.12 ml of this solution. The ratio between potassium permanganate and Mohr´s salt is 24:25. Calculate T(KMnO4/Cr)