Question

For the reaction 4 Fe + 3 O2 -> Fe2 O3, explain how you would calculate the moles of iron needed to make 10 moles of Fe2O3

Answer 1

20 moles

Step-by-step explanation:

4 Fe + 3O₂ → Fe₂O₃

The chemical equation provided is not yet balanced so let's start by balancing it.

4 Fe + 3O₂ → 2 Fe₂O₃

The equation is now balanced with 4 Fe atoms and 6 O atoms on both sides of the equation. It is important to ensure that the chemical equation is balanced, as only then will it tell you the relationship of the reactants and products in terms of mole.

Looking at the coefficients of Fe and Fe₂O₃, 4 moles of Fe is needed to make 2 moles of Fe₂O₃.

This can be simplified into the mole ratio below.

Fe: Fe₂O₃= 2: 1

This means that for every mole of Fe₂O₃, twice the amount of Fe (in moles) is needed.

Thus for 10 moles of Fe₂O₃,

amount of Fe needed

= 10 ×2

= 20 moles