Question #cec43

1 Answer
Oct 24, 2017

#= 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#