Calculating Empirical and Molecular Formulas

Scientists analyze matter and determine the contents through various means of chemical and physical testing. Mass data can be especially useful in helping to determine what elements are present in a compound and in what ratios.

Based on percent data or mass data, scientists figure out the number of moles of each atom are present in a compound. It is possible for multiple compounds to have the same percentage of elements, so percentage information alone is not sufficient to identify compounds. Other data, such as melting point or density for example, combine with empirical formula data to allow scientists to identify compounds.