A 5g sample containing FeO_4 (FeO+Fe_2O_3) and an inert impurity is treated with excess of KI solution in the presence of dilute H_2SO_4.The entire Iron converted to Ferrous ion along with liberation of Iodine.The resulting solution is diluted to 100 ml. 20 ml of the diluted solution requires 10 ml of 0.5M Na_2S_2O_3 solution to reduce the Iodine present.Amongs the following select correct statements.

A 5g sample containing FeO_4 (FeO+Fe_2O_3) and an inert impurity is tr

1.	A 5g sample containing FeO_4 (FeO+Fe_2O_3) and an inert impurity is treated with excess of KI solution in the presence of dilute H_2SO_4.The entire Iron converted to Ferrous ion along with liberation of Iodine.The resulting solution is diluted to 100 ml. 20 ml of the diluted solution requires 10 ml of 0.5M Na_2S_2O_3 solution to reduce the Iodine present.Amongs the following select correct statements.
Answer» % of `Fe_2O_3` in sample is 40% % of FeO in sample is 28% % of INERT impurity in sample is 42% % of inert impurity in sample is 32% Solution :Let the MOLES of `Fe_3O_4` is x. So MOLE of `Fe_2O_3` (in `Fe_3O_4`)=x eq of `Fe_2O_3` (in `Fe_3O_4`) =eq of KI = eq of `I_2` =eq of `Na_2S_2O_3` or 2x=0.025 or x=0.0125 mol of `Fe_2O_3` So mass of `Fe_2O_3=0.0125xx160=2g` % of `Fe_2O_3=2/5xx100=40%`