Which one of the following concentration parameters is not affected by change in temperature?

Correct option is D

Correct Answer: D. Molality

• Molality (m) = moles of solute / kilograms of solvent

  • Since mass does not change with temperature, molality remains constant.

• It is temperature-independent, making it ideal for studies involving temperature variations (e.g., boiling point elevation, freezing point depression).

• g/L (grams per litre):

  • Affected by volume changes due to temperature (since volume expands/contracts).

• Normality (N):

  • Defined as gram equivalents per litre of solution — depends on volume, so temperature-sensitive.

• Molarity (M):

  • Moles of solute per litre of solution — also changes with temperature due to volume expansion.

• For precise work in thermodynamic or colligative properties, molality is preferred.