Question

The concentration of a solution can be expressed in molarity, normality, formality and molality. Among them, which mode of expression is the most accurate for the all conditions?

• A. Molarity
• B. Formality
• C. Normality
• D. Molality

Answer 1

The correct option is D Molality

Since molarity normality and formality are calculated against the volume of the solution and the volume of the solution changes with change in temperature. Therefore, these qualities do not remain constant with temperature

$\text{Molality (m)}=\frac{\text{Moles of solute}}{\text{Mass of solvent (in kg)}}$
The molality of a solution remains independent of temperature because it involves only mass, which is independent of temperature.

Hence, the correct option is $\text{D}$