Calculating Empirical and Molecular Formulas

All compounds have a fixed, whole number ratio of atoms. It is possible to determine this ratio based on mass data gathered through experimentation. The empirical formula represents the lowest whole number ratio of elements in a compound. The molecular formula represents the actual ratio of elements in a compound. Both the empirical and molecular formulas of a compound can be calculated using molar mass information from the periodic table. In this topic, you will learn how to calculate both empirical and molecular formulas.

Essential Questions

• How are scientists able to show the number of atoms of each type in a compound?
• How can two different compounds have the same elements in the same percentages?