Question

Consider the following reaction: Fe3O4(s) + 4H2(g) --heat--> 3Fe(s) + 4H2O(l) What mass (in g) of Fe3O4 is needed to consume 2.17 g of H2? Enter only the numeric value of your answer (no units).

Answer 1

The balanced chemical reaction is as follows:

Fe₃O₄(s) + 4H₂(g) $\rightarrow$ 3Fe(s) + 4H₂O(l)

The mass of H₂ = 2.17 g

Determine the number of moles of H₂ as follows:

= 2.17 g H₂ x ( 1 mol H₂ / 2.016 g H₂)

= 1.076 mol H₂

Use the moles of H₂ and balanced chemical reaction and determine the number of moles of Fe₃O₄ as follows:

=1.076 mol H₂ x ( 1 mol Fe₃O₄ / 4 mol H₂)

= 0.2691 mol Fe₃O₄

Use the moles of Fe₃O₄ and molar mass and determine the mass of Fe₃O₄ as follows:

= 0.2691 mol Fe₃O₄ x ( 231.533 g Fe₃O₄ / 1 mol Fe₃O₄)

= 62.3 g Fe₃O₄

Thus, the mass of Fe₃O₄ needed to consume 2.17 g H₂ is 62.3 g.