Question

A sample of 10.1 g of Fe₂O₃ reacts with 12.8 g CO to yield Fe and CO₂. The balanced chemical equation is Fe₂O₃(s)+3CO(g)⟶2Fe(s)+3CO₂(g). Which substance is the limiting reactant?

A. CO
B. Fe
C. CO₂
D. Fe₂O₃

Answer 1

The limiting reactant is Fe2O3 (iron(III) oxide) since it will be consumed first based on the stoichiometry of the reaction and the initial amounts provided.

Step-by-step explanation:

To determine the limiting reactant in the given chemical reaction Fe2O3(s) + 3CO(g) → 2Fe(s) + 3CO2(g), we need to calculate the moles of each reactant and then compare them to the stoichiometric coefficients in the balanced equation.

First, calculate the moles of iron(III) oxide (Fe2O3) using its molar mass (159.7 g/mol):

moles of Fe2O3 = mass (g) / molar mass (g/mol) = 10.1 g / 159.7 g/mol ≈ 0.0632 mol

Then, calculate the moles of carbon monoxide (CO) using its molar mass (28.01 g/mol):

moles of CO = mass (g) / molar mass (g/mol) = 12.8 g / 28.01 g/mol ≈ 0.457 mol

The balanced equation shows that 1 mole of Fe2O3 reacts with 3 moles of CO. Using the stoichiometric ratio, we see that 0.0632 mol of Fe2O3 would require 0.0632 mol * 3 = 0.1896 mol of CO. Since we have 0.457 mol of CO available, which is more than the 0.1896 mol required, CO is not the limiting reactant.

Thus, Fe2O3 is the limiting reactant because it will be completely consumed first during the reaction. The answer is D. Fe2O3.