The relationship between moles, mass, and molecules is a fundamental concept in chemistry, as it connects the microscopic world of atoms and molecules with measurable laboratory quantities.
- Moles and Molecules:
- A mole is a counting unit in chemistry, just like a dozen represents 12 items.
- One mole of any substance contains Avogadro’s number of particles (6.022 × 10²³ molecules, atoms, or ions).
- This allows chemists to easily count extremely small particles by relating them to moles.
- Moles and Mass:
- The mass of one mole of a substance is equal to its molar mass, expressed in grams.
- Molar mass is calculated from the periodic table by summing the atomic masses of the elements in a compound.
- For example, one mole of water (H₂O) has a molar mass of about 18 grams.
- Mass and Molecules:
- By knowing the mass of a substance and dividing it by its molar mass, we can calculate the number of moles.
- Multiplying the number of moles by Avogadro’s number gives the number of molecules present.
In short:
- Mass → (divide by molar mass) → Moles → (multiply by Avogadro’s number) → Molecules