A mineral haematite (Fe_(2)O_(3)) contains unwanted material called gangue in addition to Fe_(2)O_(3). If 5 kg of the ore contains 2.78 kg of iron, what is the percentage purity of Fe_(2)O_(3) ?

A mineral haematite (Fe_(2)O_(3)) contains unwanted material called ga

1.	A mineral haematite (Fe_(2)O_(3)) contains unwanted material called gangue in addition to Fe_(2)O_(3). If 5 kg of the ore contains 2.78 kg of iron, what is the percentage purity of Fe_(2)O_(3) ?
Answer» Solution :Step I. Mass of pure `Fe_(2)O_(3)` in haematite `underset(bar(112+48(=160G)""2xx56=(112G)))(Fe_(2)O_(3)=2Fe)` 112 g of iron are present in `Fe_(2)O_(3) = 160 g` 2.78 kg (2780 g) of iron are present in `Fe_(2)O_(3)=(160)/(11)xx2780=3971.4g=3.9714g` Step II. Percentage purity of haematite mineral `= ("Mass of "Fe_(2)O_(3))/("Mass of mineral")=(3.9714)/(5.0)xx100=79.43%`.