Aluminium powder reacts with iron(III) oxide to produce aluminium oxide and molten iron. If 5.4 g of aluminium is reacted with 24.0 g of iron(III) oxide and the percentage yield of the reaction is 80 % , what is the actual mass (in g) of iron produced? (Given Molar mass in g mol ⁻¹ : Al =27 , Fe =56 , O =16 )

Step-by-step solution

The balanced chemical equation for the Thermite reaction is: 2 Al + Fe ₂ O ₃ Al ₂ O ₃ + 2 Fe Moles of Al = 5.4 27 = 0.2 mol Molar mass of Fe ₂ O ₃ = (2 56) + (3 16) = 112 + 48 = 160 g mol ⁻¹ Moles of Fe ₂ O ₃ = 24.0 160 = 0.15 mol From the balanced equation, 2 moles of Al require 1 mole of Fe ₂ O ₃ . Therefore, 0.2 mol of Al requires 0.1 mol of Fe ₂ O ₃ . Since 0.15 mol of Fe ₂ O ₃ is available, Fe ₂ O ₃ is in excess and Al is the limiting reagent. According to stoichiometry, 2 moles of Al produce 2 moles of Fe . T