Final answer:
To produce 3.5 moles of O2, you will need 237.82 grams of Al2O3.
Step-by-step explanation:
To determine the number of grams of Al2O3 needed to produce 3.5 moles of O2, we need to use the molar ratio from the balanced chemical equation. The balanced equation is:
2 Al + 3/2 O2 -> Al2O3
The molar ratio between O2 and Al2O3 is 3/2. This means that for every 3 moles of O2, we need 2 moles of Al2O3. Therefore, to produce 3.5 moles of O2, we will need (3.5 moles O2) * (2 moles Al2O3 / 3 moles O2) = 2.33 moles Al2O3.
To convert moles to grams, we need to multiply by the molar mass of Al2O3. The molar mass of Al2O3 is 101.96 g/mol. Therefore, 2.33 moles Al2O3 = (2.33 moles Al2O3) * (101.96 g/mol) = 237.82 grams of Al2O3.