Final answer:
Molecular formulas show the actual number of atoms of each type in a molecule, while empirical formulas show the simplest ratio. To find a molecular formula, divide the compound's molar mass by the empirical formula mass and multiply the empirical formula by this ratio.
Step-by-step explanation:
Understanding Molecular and Empirical Formulas
The distinction between molecular formulas and empirical formulas is fundamental in chemistry. A molecular formula shows the exact number of each type of atom in a molecule, whereas an empirical formula provides the simplest whole-number ratio of these atoms. Molecular formulas can sometimes be multiples of empirical formulas and are essential for conveying detailed information about the composition of a molecule.
Determination of Molecular Formulas
To determine the actual number of atoms in a molecule (molecular formula), you need the empirical formula and the molecular or molar mass. The molecular formula can be found by dividing the compound's molar mass by the empirical formula mass and then multiplying the empirical formula by this ratio (n).
Example of Molecular and Empirical Formulas
For instance, the empirical formula for glucose is CH2O, which represents the simplest ratio of carbon, hydrogen, and oxygen atoms. However, the molecular formula of glucose is C6H12O6, indicating there are six carbon, twelve hydrogen, and six oxygen atoms in a molecule of glucose. Here, the molecular formula is an integer multiple of the empirical formula.