Question

How many grams iron are needed to combine with 25.6 g of O to make Fe2O3?

Answer 1

Dear student,

The reaction is
$4Fe+3O_2\to F{e}_2{O}_3$

25.6 g O2 x (1 mole O2 / 32.0 g O2) = 0.800 moles O2

The balanced equation tells us that it takes 4 moles of Fe to react with 3 moles of O2.

0.800 moles O2 x (4 moles Fe / 3 moles O2) = 1.07 moles Fe

1.07 moles Fe x (55.9 g Fe / 1 mole Fe) = 59.8 g Fe

Regards