What is the empirical formula?

The empirical formula is defined as the simplest whole number ratio of elements present in a compound. This means that the empirical formula provides a reduced form of the molecular formula, focusing solely on the relative quantities of different atoms without indicating their actual numbers. For example, if a compound has a molecular formula of C6H12O6 (glucose), its empirical formula would be CH2O, reflecting the simplest ratio of carbon, hydrogen, and oxygen atoms.

Understanding the empirical formula is crucial in chemistry as it helps chemists determine the basic composition of substances and is often used in stoichiometric calculations. The other responses do not accurately represent the concept of an empirical formula: it neither conveys molecular weight, nor does it describe the structural arrangement of atoms or the total number of atoms present in a molecule.