Molecular formulas

Molecular formula

Molecular formulas indicate the numbers of atoms of each element in a molecule of a molecular substance. They are the same as the empirical formula for many molecules, and an integer multiple of the empirical formula for others. For water, the empirical and molecular formulas are both H₂O. An example in which they differ is glucose for which the empirical formula is CH₂O (ratio 1:2:1), and the molecular formula is C₆H₁₂O₆ (number of atoms 6:12:6). A molecular formula provides more information about a molecule than its empirical formula, but is more difficult to establish.