How does the osmotic pressure of a solution vary with the temperature?

increases with increase in temperature

The correct answer is Option (3) → increases with increase in temperature

The osmotic pressure (Π) of a dilute solution is described by the van't Hoff equation, which is analogous to the ideal gas law:

Π=CRT

Where:

• Π = Osmotic Pressure
• C = Molar concentration of the solute (moles/volume, mol/L)
• R = Ideal gas constant
• T = Absolute temperature (in Kelvin)

Dependence on Temperature

For a fixed volume of solution, the molar concentration (C) remains essentially constant (since the moles of solute and volume of solvent are fixed). Since R is a constant, the van't Hoff equation shows a direct proportionality between osmotic pressure and absolute temperature:

Π∝T

Therefore, if the absolute temperature (T) increases, the osmotic pressure (Π) must also increase.