Question

what is the difference between an empirical formula and a molecular formula? how are the two formulas related mathematically?

Explanation:

An empirical formula gives the simplest whole - number ratio of atoms in a compound. A molecular formula is the actual number of atoms of each element in a molecule. Mathematically, the molecular formula is a multiple ($n$) of the empirical formula, where $n$ is a positive integer. If the empirical formula is $EF$ and the molecular formula is $MF$, then $MF = n\times EF$, and $n=\frac{\text{molar mass of compound}}{\text{molar mass of empirical formula}}$.

Answer:

An empirical formula represents the simplest whole - number ratio of atoms in a compound. A molecular formula shows the actual number of atoms of each element in a molecule. The molecular formula is a multiple of the empirical formula, with the multiple $n=\frac{\text{molar mass of compound}}{\text{molar mass of empirical formula}}$.