What is an empirical formula?
It's a ratio formula of all the elements in the compound.
A ratio formula doesn't say anything about the actual numbers of atoms and how they are interconnected.
By burning a carbon-hydrogen compound and measuring the water and
This means the compound has a molecular formula of
So it could be
Determining the molecular mass (step two) may lead to a molecular formula, which tells us the right number of atoms in the molecule, but still nothing about how they are connected.
The smallest whole number ratio of each element in one atom of a compound.
For example the Empirical formula of Butane (