the.com/molality
Moles of solute per kilogram of solvent — chemistry's way of ignoring volume's mood swings.
means A way of measuring concentration by dividing the moles of solute by the mass (in kilograms) of the solvent, rather than by the volume of the solution.
from Built from 'mole,' the chemist's counting unit for particles (coined in the early 20th century from the German 'Mol,' itself short for 'Molekül,' molecule), plus the suffix '-ality' tacked on to make it sound properly scientific — and crucially chosen to echo yet distinguish itself from 'molarity,' which measures concentration per liter of solution instead of per kilogram of solvent. The one-letter difference between the two words has tormented chemistry students ever since.
- vs molarity
- uses mass not volume, so temperature cannot wreck it
- symbol
- lowercase m, easily confused with molarity's capital M
- why it matters
- key for boiling point and freezing point shifts
- unit
- mol/kg, sometimes called the molal