Question

Iron oxide, known as hematite, is the main source of iron for the steel industry. It is created when iron and oxygen combine in a thermal decomposed reaction. It can be described using the equation 4Fe + 3O2 = 2Fe2O3. If 19.2 g of O2 reacts with iron to form 63.84 g of oxide, how much iron in grams was used in the reaction?

Answer 1

The balanced equation for the reaction is:

4Fe + 3O2 -> 2Fe2O3

We are given the mass of oxygen and the mass of iron oxide produced. To find the mass of iron used in the reaction, we need to use stoichiometry to relate the masses of the reactants and products.

First, we can calculate the molar mass of Fe2O3:

Fe2O3 = 2(55.845 g/mol) + 3(16.00 g/mol) = 159.69 g/mol

Next, we can use the mass of iron oxide produced to find the number of moles of Fe2O3:

63.84 g Fe2O3 × (1 mol Fe2O3/159.69 g Fe2O3) = 0.400 mol Fe2O3

Since the reaction produces 2 moles of Fe2O3 for every 4 moles of Fe, we can find the number of moles of Fe:

0.400 mol Fe2O3 × (4 mol Fe / 2 mol Fe2O3) = 0.800 mol Fe

Finally, we can use the molar mass of Fe to convert the number of moles to grams:

0.800 mol Fe × 55.845 g/mol = 44.68 g Fe

Therefore, 44.68 grams of iron were used in the reaction.