Question

find the empirical formula of an oxide of iron which has 69.9% of iron

Answer 1

% of iron by mass = 69.9 % [Given]% of oxygen by mass = 30.1% [Given]Relative moles of iron in iron oxide: Relative moles of oxygen in iron oxide: Simplest molar ratio of iron to oxygen:= 1.25: 1.88= 1: 1.5 2: 3∴ The empirical formula of the iron oxide is Fe2O3.