When 2.34 g of pure iron is allowed to react with an excess of oxygen, 3.35 g of the final compound is produced. Determine the formula of the compound.

Question

Quizplus · Accepted Answer

The mass of oxygen that reacted with iron is 3.35 g - 2.34 g = 1.01 g. The molar mass of Fe is 55.85 g/mol and O is 16.00 g/mol. Moles of Fe = 2.34 g / 55.85 g/mol = 0.0419 mol. Moles of O = 1.01 g / 16.00 g/mol = 0.0631 mol. The simplest ratio of Fe:O is approximately 2:3, which corresponds to Fe₂O₃.

When 234 G of Pure Iron Is Allowed to React with with an Excess