what is the total mass of iron in a 1.0 mole of Fe2O3

Question

what is the total mass of iron in a 1.0 mole of Fe2O3

Answer 1

Anna,

 

I would like to add onto Marlene's response. Although yes you do account for the total mass of Iron( Fe³⁺ ) to get you total mass of Iron, the atomic mass and atoms of Oxygen are irrelevant to this problem. Rather than adding the whole atomic mass of oxygen and Iron, just account for Iron. The stochiometry then is as follows:

 

1.0 mol Fe₂O₃ x (2 mol Fe/1 mol Fe₂O₃) x (55.845 g Fe/1 mol Fe) = 111.69 g Fe, about 112g Fe

 

Answer 2

Hi Anna,

 

In Fe₂O₃ there are 2 iron atoms and 3 oxygen atoms.

 

Iron has atomic mass of 55.845

Oxygen has atomic mass of 15.9994

 

2(55.845) + 3(15.9994) = 111.69 + 47.9982 = 159.6882 grams in a mole of Fe₂O₃