Question

Fe2O3 (s) + 2 Al (s) ---> 3 Fe (l) + Al2O3 (s) Based on the thermite reaction, how much aluminum oxide (Al2O3) is formed from 8.0 grams of aluminum (Al)?

Answer 1

15.3 g

Step-by-step explanation:

• Fe₂O₃ (s) + 2Al (s) → 3Fe (l) + Al₂O₃ (s)

First we convert 8.0 grams of aluminum into moles, using its molar mass:

• 8.0 g Al ÷ 27 g/mol = 0.30 mol Al

Then we convert 0.30 moles of aluminum into moles of aluminum oxide, using the stoichiometric coefficients:

• 0.30 mol Al *
  `(1molAl_2O_3)/(2molAl)` = 0.15 mol Al₂O₃

Finally we convert 0.15 moles of Al₂O₃ into grams, using its molar mass:

• 0.15 mol Al₂O₃ * 102 g/mol = 15.3 g Al₂O₃