What is molality a measure of?

Molality is defined as the number of moles of solute divided by the mass of the solvent in kilograms. This measure is crucial in chemistry because it expresses the concentration of a solution based on the mass of the solvent rather than the volume of the solution. This is particularly useful in situations where the temperature varies, as the volume of a solution can change with temperature, but the mass of the solvent remains constant.

In terms of applications, molality is often used in colligative property calculations, such as determining boiling point elevation and freezing point depression, where changes in properties depend on the number of solute particles in the solvent rather than the overall volume of the solution. As such, understanding molality is essential for accurately conducting experiments and predicting how solutions behave under various conditions.