A 6.0 gm sample contained Fe_3O_4, Fe_2O_3 and inert materials. It was treated with an excess of KI in acid, which reduced all iron to Fe^(2+). The resulting solution was diluted to 50 ml, and a 10 ml sample of it was taken. The liberated iodine in the small sample was titrated with 5.5 ml of 1M Na_2S_2O_3 solution yielding S_4O_6^(2–). Theiodine from another 25 ml sample was extracted, after which the Fe^(2+) was titrated with 3.2 ml of 1.0 M MnO_4^– in H_2SO_4 solution. Calculate the percentage of Fe_3O_4 and Fe_2O_3, in the original mixture.

A 6.0 gm sample contained Fe_3O_4, Fe_2O_3 and inert materials. It was

1.	A 6.0 gm sample contained Fe_3O_4, Fe_2O_3 and inert materials. It was treated with an excess of KI in acid, which reduced all iron to Fe^(2+). The resulting solution was diluted to 50 ml, and a 10 ml sample of it was taken. The liberated iodine in the small sample was titrated with 5.5 ml of 1M Na_2S_2O_3 solution yielding S_4O_6^(2–). Theiodine from another 25 ml sample was extracted, after which the Fe^(2+) was titrated with 3.2 ml of 1.0 M MnO_4^– in H_2SO_4 solution. Calculate the percentage of Fe_3O_4 and Fe_2O_3, in the original mixture.
Answer» ANSWER :34.8, 49.33