Step-by-step explanation:
To determine the number of grams of oxygen needed to react completely with 7.56 moles of iron, we need to balance the equation first:
Fe + O2 -> Fe2O3
2 Fe + 3 O2 -> 2 Fe2O3
Next, we can use the mole ratio between the reactants to find the number of moles of oxygen required for the reaction.
From the balanced equation, we can see that for every two moles of iron, three moles of oxygen are required. So, for 7.56 moles of iron, we would need:
7.56 moles Fe * (3 moles O2 / 2 moles Fe) = 11.34 moles O2
Finally, to convert moles to grams, we use the molar mass of oxygen gas, which is 32 g/mol.
11.34 moles O2 * (32 g/mol) = 364.48 g O2
So, 364.48 g of oxygen gas would be needed to react completely with 7.56 moles of iron according to the equation Fe + O2 -> Fe2O3.