Question

For the reaction 2Fe + O2 → 2FeO, how many grams of iron oxide are produced from 42.4 mol of iron?

Answer 1

In the balanced reaction

2 Fe + O₂   →   2 FeO

2 moles of iron (Fe) react with 1 mole of molecular oxygen (O₂) to produce 2 moles of iron oxide (FeO). The ratio of Fe to FeO is 1-to-1, so if one starts with 42.4 mol of Fe, one will end up with the same amount of FeO, 42.4 mol.

Look up the molar mass of Fe and O:

• Fe = 55.845 g/mol

• O = 15.999 g/mol

Then the molar mass of FeO is approximately 71.835 g/mol, and so the mass of 42.4 mol of FeO is

(42.4 mol) × (71.835 g/mol) ≈ 3050 g