Consider the following reaction: 4Fe+3O2=2Fe2O3

Question

How many grams of oxygen gas are needed to react completely with 44.2 grams of iron

Answer 1

4Fe + 3O₂ ==> 2Fe₂O₃ ... balanced equation

atomic mass Fe = 55.85 g/mol

molar mass O2 = 32 g/mol

Use dimensional analysis to answer the question:

44.2 g Fe x 1 mol Fe / 55.85 g x 3 mol O₂ / 4 mol Fe x 32 g O₂ / mol O2 = 19.0 g O₂ (3 sig. figs.)