Question

Iron (iii) oxide, fe2o3(s), is more commonly known as rust. show all calculations and a full solution in problem solving format. include units and the correct number of significant digits. a) what amount of iron (iii) oxide is in a 77.2g sample? b) what amount of oxygen atoms is in this same sample?

Answer 1

Answer: a) 0.48 mol Fe2O3

b) 33.3g Oxygen

77.2g x 1mole/ 159.69 grams = 0.48 moles of Fe2O3

if .48 moles of Fe2O3 exist then there must have been 0.48 moles of oxygen

Oxygen is 15.999g/mol x 0.48 = 33.3 g of Oxygen , but if problem would have asked how many grams of O2, since Oxygen is supplied as O2, the grams of O2 would be 16.65, or 16.7g rounded off