Objective: To demonstrate the experimental determination of an empirical formula
for an oxide using mass measurements.

Know

Empirical Formula vs Molecular Formula
Calculation of an empirical formula from mass measurements
The general procedure for this is:

1. Determine masses of each element which have reacted
2. Convert masses of each to moles
3. Convert moles to a ratio of moles by dividing the number of moles of each element
by the smallest number of moles found.

This should produce a simple whole number ratio, which is the empirical formula.
However, if the initial ratio turns out to be 1:1.5, for example,
then multiply both of these by 2, to get 2:3, which is the empirical formula in this case.

This is also covered in the Chem 1 text, "Chemistry-Science of Change, 3rd. ed."
in section 2-1, pgs. 42-49.