3.10: Molecular Formulas
- Page ID
- 55709
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Molecular formulas tell which—and how many—atoms are in a particular molecule. A molecule’s composition is exact. Even a small change in composition results in a very different molecule. For example, hydrogen peroxide (H2O2), which has just one more oxygen atom than water (H2O), is a bleach and disinfectant. The molecular formula does not, however, tell how the atoms are arranged in the molecule. For example, table sugar (sucrose) and milk sugar (lactose) both have the same molecular formula (C12H22O11), but their atoms are arranged differently (see Figure 5.1).