# What is the practical difference between "molarity", and "molality"?

May 2, 2017

At low to moderate concentrations IN AQUEOUS solution, the difference is minimal and can be ignored.......

#### Explanation:

By definition................

$\text{Molarity"="Moles of solute (mol)"/"Volume of solution (L)}$, and thus has units of $m o l \cdot {L}^{-} 1$.

$\text{Molality"="Moles of solute (mol)"/"Mass of solvent (kg)}$, and thus has units of $m o l \cdot k {g}^{-} 1$.

Molality is often preferred in that it is independent of density, and thus independent of temperature.