Here's the equation:
Fe2 O3 + 2Al → 2Fe + Al2 O3
Here's the question.
What mass of Al will react with 150g of Fe2 O3?
In every 2 moles Al you need 1 mole Fe2O3
moles = mass / molar mass
moles Fe2O3 = 150 g / 159.69 g/mol
= 0.9393 moles
moles Al needed = 2 x moles Fe2O3
= 2 x 0.9393 mol
= 1.879 moles Al needed
mass = molar mass x moles
mass Al = 26.98 g/mol x 1.879 mol
= 50.69 g
= 51 g (2 sig figs)
So the mass of Al that will react with 150g of Fe2 O3 is 51 grams.
