if 11.80 g of iron reacts with 5.06 g of oxygen, determine the empirical formula of the oxide?

Answer 1

moles = grams/atomic mass
mols Fe atoms = 11.8/55.85 = 0.211
mols O atoms = 5.06/16 = 0.316
Now want to find the ratio of these two to each other with the smallest number being no less than 1.00. The easy way to do that is to divide both numbers of the smallest; i.e.,
Fe = 0.211/0.211 = 1.00
O = 0.316/0.211 = 1.498 which rounds to 1.5
We know that compounds exist with atoms in the ratio of small whole numbers so we can see that a ratio of 1.00 to 1.5 is 2 to 3 or if we multiply both numbers by 2 to get whole numbers it will be Fe of 2 and O of 3 so the simplest empirical formula is Fe2O3.

Answer 2

thank you sir for your help