Question

Differentiate between Molarity and Molality by giving examples.

Hint:

Molarity depends on volume (temperature-sensitive), while molality depends on mass (temperature-independent).

Answer 1

Molarity (M): The number of moles of solute dissolved in 1 liter of solution. \[ M = \frac{\text{moles of solute}}{\text{volume of solution (L)}}. \] Example: A 1 M solution of NaCl contains 1 mole of NaCl in 1 liter of solution. - 

Molality (m): The number of moles of solute dissolved in 1 kg of solvent. \[ m = \frac{\text{moles of solute}}{\text{mass of solvent (kg)}}. \] Example: A 1 m solution of NaCl contains 1 mole of NaCl in 1 kg of solvent.