Question

Felicity and Dawson are conducting an investigation to determine the empirical formula of iron oxide. They start with an 85.65g piece of iron metal and burn it in the air. The mass of the iron oxide produced is 118.37. Felicity thinks the empirical formula of iron oxide is Fe3O4 and Dawson thinks it is if FeO. Use what you know about how to determine the empirical formula of a compound to provide an argument in support of Felicity or Dawson.

Answer 1

Mass of iron: 86.65
Moles of iron: 85.65 / 56 = 1.53

Mass of oxygen: 118.37 - 86.65 = 32.72
Moles of oxygen: 32.72 / 32 = 0.99 1.02

The molar ratios of the two are approximately similar; therefore, Dawson's conclusion is more correct.