How do you determine an empirical formula?
See explanation below:
The empirical formula is essentially a compound in which the atom-atom ratio of different elements is in the smallest whole number ratio. This doesn't necessarily need to be the actual chemical formula of the compound.
To determine an emperical formula from a compound, all you'd need to do is check the amounts of each atom present, and see if you can simplify the ratio of atoms.
So for example, consider the chemical formula for glucose:
The empirical formula of this is would be
There are more complicated problems involving empirical formula. To see some of those, you can watch the two videos below:
Hope that helps :)