The mole concept is a fundamental principle in chemistry that relates the number of particles to measurable quantities like mass and volume. A mole contains Avogadro's number (6.02 x 10^23) of particles, whether atoms, molecules, or formula units. This concept allows chemists to bridge the microscopic world of atoms with macroscopic measurements in the lab. Understanding moles is crucial for stoichiometry, gas laws, and solution chemistry.
Key points:
• One mole of a substance contains 6.02 x 10^23 particles
• The mass of one mole of a substance is its molar mass (in g/mol)
• For gases, one mole occupies 22.4 L at STP
• Moles can be calculated from mass, number of particles, or gas volume