Explain why concentration in terms of molality is preferred in comparison to molarity.

Explanation

(1) Molarity is the concentration in moles per litre of the solution. It depends upon temperature. As the temperature changes volume of the solution change, hence the molarity changes.
(2) Molality is the concentration in moles per kilogram of the solvent. Since the mass of the solvent is independent of temperature, the molality is independent temperature. Therefore molality (m) is preferred in comparison with molarity (M).