Colligative Properties — Predicted 2026
AI-Predicted Question Angles for UPSC 2026
Comparison of colligative properties for multiple electrolyte solutions.
highNEET frequently tests the ability to compare the magnitude of colligative properties (e.g., highest boiling point, lowest freezing point, highest osmotic pressure) for different solutions of varying concentrations and electrolyte types. This requires accurate calculation of the van't Hoff factor ($i$) and its product with molality/molarity ($i \times m$ or $i \times C$). Questions might involve solutions like 0.1 M NaCl, 0.1 M CaCl$_2$, 0.1 M glucose, and 0.1 M urea, forcing students to apply the concept of dissociation and the van't Hoff factor correctly.
Calculation of molecular mass from osmotic pressure for macromolecules.
mediumOsmotic pressure is particularly useful for determining the molecular masses of large molecules like proteins or polymers due to its sensitivity at low concentrations. Questions might provide the osmotic pressure, temperature, and mass concentration (e.g., % w/v or g/L) of a macromolecule solution and ask for its molar mass. This tests the application of the van't Hoff equation and the ability to convert between different concentration units, often with $i=1$ as macromolecules typically don't dissociate.
Combined problems involving two colligative properties or degree of dissociation/association.
highA common and slightly more challenging question type involves using one colligative property to determine an unknown (like molality or van't Hoff factor) and then using that information to calculate another colligative property. For instance, a problem might give the freezing point depression and ask for the boiling point elevation or osmotic pressure. Alternatively, the observed colligative property might be given to calculate the degree of dissociation ($\alpha$) or association of a solute, requiring the formula $i = 1 + (n-1)\alpha$ or $i = 1 + (\frac{1}{n}-1)\alpha$.