Understanding the difference between empirical and molecular formulas is important in Grade 12 Chemistry, especially when studying stoichiometry.

Empirical Formula: The empirical formula shows the simplest whole-number ratio of the elements in a compound. For example, hydrogen peroxide (H₂O₂) has an empirical formula of HO. This means that the simplest ratio of hydrogen to oxygen is 1:1.

Molecular Formula: The molecular formula tells us the actual number of atoms of each element in a molecule. For hydrogen peroxide, the molecular formula is H₂O₂. This means there are 2 hydrogen atoms and 2 oxygen atoms in each molecule.

Key Differences:

1. Definition:

   • Empirical Formula: Shows the simplest ratio of elements.
   • Molecular Formula: Gives the actual number of atoms in a molecule.

2. Examples:

   • Empirical Formula Example: For glucose (C₆H₁₂O₆), the empirical formula is CH₂O. This shows that the ratio of carbon to hydrogen to oxygen is 1:2:1.
   • Molecular Formula Example: The molecular formula for glucose stays C₆H₁₂O₆.

3. Usefulness:

   • Empirical formulas help us understand the basic makeup of a substance. Molecular formulas give us specific details about the molecule, which helps in calculating reactions and doing stoichiometry.

By learning about both formulas, you can better understand chemical compounds and improve your calculations in stoichiometry!