Read the passage carefully and answer the questions. The osmotic pressure is one of the four colligative properties which depends on the number of particles of solute in the solution, irrespective of their nature. The osmotic pressure is equal to the product of concentration, gas constant and temperature. It is the most commonly used property for the determination of the molar mass of biomolecules. In many situations, the molecules get dissociated or associated when they are dissolved in a solvent, thereby changing the number of molecules in the solution. As a result, an abnormal molecular mass is obtained. The extent of dissociation or association is given by van't Hoff factor (i), which is the ratio of normal molar mass to abnormal molar mass. It is related with the degree of association or ionization. The introduction of van't Hoff factor in the osmotic pressure equation modifies the equation. |
How is the osmotic pressure of a concentrated solution related to the osmotic pressure of a dilute solution of the same substance at a given temperature? |
Lower than that of its dilute solution. Same as its dilute solution. Higher than that of its dilute solution. Cannot compare on concentration basis until we know the nature of that solute. |
Higher than that of its dilute solution. |
The correct answer is Option (3) → Higher than that of its dilute solution. Osmotic pressure (П) is directly proportional to the concentration of solute particles: $\Pi = i C R T$ For a concentrated solution, C is higher → osmotic pressure increases. Therefore, the osmotic pressure of a concentrated solution is higher than that of a dilute solution at the same temperature. |