Question

In which mode of expression, the concentration of a solution remains independent of temperature?

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

Answer 1

Answer: (D)

Molality

Molarity, normality, and formality are calculated against the volume of the solution. The volume of the solution changes with change in temperature. Therefore, these quantities do not remain constant with temperature.

$Molality\left(m\right)=\frac{\text{Moles of solute}}{\text{Mass of solvent in kg}}$

The molality of a solution remains independent of temperature because it involves only mass which is independent of temperature.

Hence, option D is correct.