Question

What is the empirical formula for `C_6H_6`?

Answer 1

It is simply `CH`.

Explanation:

The empirical formula is the simplest whole number defining constituent atoms in a species. The molecular formula is A MULTIPLE of the empirical formula.

If we were given a sample of benzene, we could perform combustion analysis and get an empirical formula of `CH`, after the benzene was combusted and the oxidation products of `CO_2` and `H_2O` were very accurately measured on a gas chromatograph. We would need a molecular mass determination before we could supply the molecular formula.