ABSTRACT
The simplest formula (or empirical formula) is the simplest whole number ratio of elements in a compound. This type of formula is the only formula commonly used for ionic compounds or for those compounds that come as a large three-dimensional array. The simplest (empirical) formula (simplest whole number ratio) is the only formula necessary for ionic compounds. Molecular formulas, which apply to most covalent compounds, can be found from the simplest formula if the actual molar mass of the compound is known. A true molecular formula must be either identical to, or a multiple of, the simplest whole number ratio of elements in one molecule. The multiple relates the elemental simplest ratio to the actual numbers of atoms in a molecular formula and can be determined if the actual molar mass of the compound is known from other types of analysis.
