text: chemistry question please help fast!!!? iron ore is converted to pure iron by the folllowing reaction which occures at high temperature.  fe2o3 + 3co -----> 2 fe = 3 co2  a 1600 g sample of iron reacted completely to form 558 g of pure iron. what was the percent of fe2o3 (160 grams) was in the original sample?  please explain the steps you took to solve it..... ok. we know 558g of iron were obtained. 1 mol of iron weighs 55.8g, so 10moles of iron were obtained.  5fe203 + 15co -> 10 fe + 15 co2  so we must have had 5moles of fe2o3 in the original sample.  1 mole of fe2o3 weighs 160g (given) 5 moles weighs 800g  and, in the original sample of ore, 800 out of 1600g was fe2o3 - or 50%