mol
Noun: 1. A unit of measurement in chemistry: The amount of a substance that contains as many elementary entities (atoms, molecules, ions, or other particles) as there are atoms in exactly 12 grams of carbon-12. This number is approximately 6.022 × 10²³ (Avogadro's number). It is the base unit for amount of substance in the International System of Units (SI).
The word mol is used to quantify an amount of a chemical substance. It allows chemists to relate masses of substances to the number of atoms or molecules they contain. - It is a singular noun. The standard plural form is moles. - It is often used with a number or a descriptive term (e.g., one mol, several moles, a fraction of a mol).
- Noun:
- One mol of water (H₂O) has a mass of about 18 grams.
- The reaction requires two moles of hydrogen for every one mole of oxygen.
- The concentration of the solution was 0.5 mol per liter.
- Molar mass: The mass of one mole of a given substance, typically expressed in grams per mole (g/mol).
- The molar mass of sodium chloride (NaCl) is 58.44 g/mol.
- Molarity (M): A unit of concentration defined as the number of moles of solute per liter of solution.
- A 1 M solution contains one mole of solute per liter.
- Mole (n): The standard full spelling and more common form of the unit. "Mol" is an accepted symbol and shorthand.
- Gram-molecule (n, historical): An older term essentially synonymous with mole, referring to the molecular weight in grams.
- Gram-molecular weight (n, historical/contextual): Refers to the mass in grams of one mole of a molecular substance.
The word mol has only one primary scientific meaning as defined above. It is not to be confused with: - Mole (animal): A small, burrowing mammal. - Mole (skin mark): A small, dark spot on the skin. - Mole (spy): An agent who infiltrates an organization.
In scientific writing, the symbol mol is used after a numerical value (e.g., 3 mol). The term is internationally standardized and fundamental to stoichiometric calculations in chemistry.
- the molecular weight of a substance expressed in grams; the basic unit of amount of substance adopted under the Systeme International d'Unites