mol
Units & Measurements abbreviation · Metric and SI Unit
| Stands for | Mole |
|---|---|
| Categories | Units & Measurements |
mol stands for Mole, a metric and SI unit abbreviation.
The SI base unit for amount of substance, defined since 2019 as exactly 6.02214076 × 10^23 elementary entities, the Avogadro number. Chemists use it to count atoms and molecules by weighing: 1 mol of water has a mass of about 18 g.
Example: Dissolve 0.25 mol of sodium chloride in enough water to make 500 mL of solution.
Usage notes
The name comes from German Mol, short for Molekul, introduced by chemist Wilhelm Ostwald around the turn of the 20th century. Before 2019 the mole was defined as the number of atoms in 12 g of carbon-12. Chemistry students celebrate Mole Day on October 23 from 6:02 a.m. to 6:02 p.m., echoing 6.02 × 10^23.