123. Solving a chemistry problem

13. A solution obtained from a sample of ferrite composition Fe2O3-BaO weighing 0.3822 g was passed through a column with an anion exchanger to separate iron. The resulting solution was neutralized to pH=10, 25.00 ml of 0.025 M EDTA was introduced, the excess of which was titrated with 0.0200 M magnesium chloride, spending 20.92 ml. Calculate mass fractions (%) of oxides in ferrite.