Determine the empirical formula of potassium oxide.

A student determined the empirical formula of potassium oxide using the procedure of this experiment. She obtained the following data:

Mass of crucible and cover, g 28.288
Mass of crucible,cover, and K,g 28.709
Mass of crucible, cover, and potassium oxide,g 28.793

Use these data to determine the empirical formula of potassium oxide. The molar mass of potassium (K) is 39.10 g/mol.

28.793 - 28.709 = 0.084 g O

28.709 - 28.288 = 0.421 g K

(0.084 g O) / (15.99943 g O/mol) = 0.005250 mol O
(0.421 g K) / (39.10 g K/mol) = 0.010767 mol K

Divide by the smaller number of moles:
(0.005250 mol O) / 0.005250 = 1.00
(0.010767 mol K) / 0.005250 = 2.05
Round to the nearest whole numbers to find the empirical formula:
K2O