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Formulas
A molecular formula shows the exact number of atoms in a single molecule, like a complete shopping list. An empirical formula shows the simplest ratio of those atoms, like the basic proportions in a recipe.
Need to know
What you need to know
- **Molecular Formula**: Shows the total number of atoms of each element in a molecule (e.g., glucose is C₆H₁₂O₆).
- **Empirical Formula**: Shows the simplest whole-number ratio of atoms (e.g., for glucose, the ratio 6:12:6 simplifies to 1:2:1, so the empirical formula is CH₂O).
- The molecular formula is always a whole-number multiple of the empirical formula.
Explanation
From Atoms to Formulas
- Molecular formula gives the actual atom count in a molecule.
- Empirical formula is the simplest whole-number ratio of atoms.
- Coefficients in an equation balance atom counts (conservation of mass).
- Ionic compounds are represented by formula units, not molecules.