You can work out the molecular formula from the empirical formula, if you know the relative mass formula (M r) of the compound. Add up the atomic masses of the atoms in the empirical formula.

The empirical rule states that almost all observed data for a normal distribution will fall within three standard deviations of the mean or average. What Is the Empirical Rule? The empirical rule ...

of~an~element} = \frac{mass~of~an~element~in~the~compound}{relative~formula~mass~M_r} \times 100\) There are six atoms of hydrogen in the compound, so the mass of hydrogen is 6 × 1 = 6.