Question

Which of the following is colligative property?
A. Surface tension
B. Viscosity
C. Refractive index
D. Osmotic pressure

Answer 1

Hint: The colligative property is the property which depends only on the number of solute particles present in the solution and not on the nature of the solute particles.

Complete step by step answer:
-A colligative property is defined as the property of solution that depends on the ratio between the total number of solute particles present in the solution to the total number of solvent particles.
-The colligative property does not depend on the chemical nature of the components present in the solution.
-In dilute solution, the non-volatile solute exhibits some properties which are dependent on the number of solute particles and not on the type of solute.
-Surface tension is not related to the number of solute particles. Thus it is not a colligative property.
-Viscosity is the resistance of the fluid to change its shape. It is also not a colligative property.
-Refractive index is the ratio of the speed of light in a vacuum to the speed of light in a specific medium. It is also not a colligative property.
-When a semipermeable membrane is put between the solvent and solution, the membrane will allow the movement of solvent through the semipermeable membrane but not the bigger solute particles. The phenomenon of the movement of solvent from a semipermeable membrane from higher concentration to lower concentration is called osmosis.
-The flow of solvent is stopped by putting extra pressure which is called osmotic pressure. Osmotic pressure is a colligative property which does not depend on the nature of the solute but on the number of solutes.
Therefore, the correct option is D.

Note:
The osmotic pressure is directly proportional to the molarity and temperature where molarity is the number of solute dissolved in one liter of solution.