| Feature | Molarity (M) | Molality (m) | Mole Fraction (x) |
|---|---|---|---|
| Definition | mol solute / L solution | mol solute / kg solvent | nᵢ / n_total |
| Units | mol/L (M) | mol/kg | Dimensionless |
| Temperature dependent? | Yes (volume changes) | No (mass constant) | No (mass constant) |
| Denominator refers to | Solution (solute + solvent) | Solvent only | All components |
| NEET use case | Titrations, lab calculations | Colligative properties | Vapour pressure problems |
| Increases with temperature? | Decreases (solution expands) | No change | No change |
| Formula from mass% | M = (1000 × d × w%) / (M_r × 100) | m = (1000 × w%) / (M_r × (100−w%)) | x = (w%/M_r) / (w%/M_r + (100−w%)/M_solvent) |
Additional comparison — Normality vs Molarity:
| Feature | Normality (N) | Molarity (M) |
|---|---|---|
| Based on | Equivalents | Moles |
| Formula | N = M × n-factor | M = mol/L |
| Reaction-specific? | Yes (n-factor changes) | No |
| Example: | N = 2M (neutralisation) | M = 1M |