Here's how to understand it:
* Empirical Formula: Represents the simplest whole-number ratio of atoms in a compound. It doesn't necessarily tell you the exact number of atoms in a molecule, but it provides the relative proportions.
* Molecular Formula: Represents the actual number of atoms of each element in a molecule.
Example:
* Glucose: Its molecular formula is C₆H₁₂O₆, meaning it has 6 carbon, 12 hydrogen, and 6 oxygen atoms.
* Empirical Formula of Glucose: CH₂O (simplest whole-number ratio of 1:2:1).
Determining Empirical Formula:
1. Find the mass of each element in the compound. This can be done experimentally or provided in the problem.
2. Convert the masses to moles using the molar mass of each element.
3. Divide the number of moles of each element by the smallest number of moles. This gives you the simplest whole-number ratio of atoms.
4. If the resulting numbers are not whole numbers, multiply them by the smallest whole number that makes them all whole.
Key Point: The empirical formula is essential for understanding the composition of a compound. It helps to identify unknown compounds and predict their properties.
