Question

Question #cec43

Answer 1

`= 27.98gFe`

Explanation:

Rewrite your compound so you can visually see how many moles you have of each element.

Iron (III) Oxide `-> Fe_2O_3`

Then use basic conversion factors:

Iron has `55.845 g/(mol`.
Oxygen has `15.99 g/(mol`.

There are 2 moles of Iron and 3 moles of Oxygen in Iron (III) Oxide.

We want to end up with grams of iron.

`2(55.845) + 3(15.99) = 159.66`

`159.66g` `Fe_2O_3` per mole.

`40.0g` `Fe_2O_3*(1mol Fe_2O_3)/(159.66g Fe_2O_3)*(2molFe)/(1molFe_2O_3)*(55.845gFe)/(1molFe)`

`= 27.98gFe`