Which of the following is a colligative property?
A
Relative lowering of fluid pressure
B
Decrease in boiling point
C
Decrease in freezing point
D
Change in volume after mixing
Correct Answer: Decrease in freezing point
Decrease in freezing point is the correct colligative property, known as ‘Depression in freezing point’. This is caused by solute particles present on the surface which lowers the equilibrium solid-vapor pressure. Therefore, a lower freezing temperature is required to match the pressure outside. The other correct colligative properties are 1.) Relative lowering of vapor pressure, 2.) Elevation in boiling point, 3.) Depression in freezing point and 4.) Osmotic pressure.