What is meant by Colligative properties? Name the four colligative properties and explain how they are used for the determination of molar mass of non-volatile solutes.

Q: What is meant by Colligative properties? Name the four colligative properties and explain how they are used for the determination of molar mass of non-volatile solutes.

Definition of Colligative Properties\nProperties of dilute solutions that depend only upon the number of solute particles (molecules or ions) relative to the total number of particles present in the solution, and not on the chemical nature or identity of the solute, are called colligative properties (derived from the Latin word colligare meaning 'to bind together'). Four Major Colligative Properties Relative Lowering of Vapour Pressure: The lowering of vapour pressure depends on the mole fraction of the non-volatile solute particles. Elevation of Boiling Point: The increase in the boiling point of a solvent due to the addition of a non-volatile solute. Depression of Freezing Point: The lowering of the freezing point of a solvent upon the addition of a non-volatile solute. Osmotic Pressure: The excess hydrostatic pressure that must be applied to prevent the passage of solvent molecules into the solution through a semipermeable membrane. Determination of Molar Mass Using Colligative Properties\nAll colligative properties are directly or inversely proportional to the number of moles of solute, which allows chemists to calculate the molar mass of unknown non-volatile solutes. From Relative Lowering of Vapour Pressure: $\frac{p1^0 - p1}{p1^0} = \frac{W2 M1}{M2 W1}$, where $M2$ can be calculated. From Elevation of Boiling Point: $\Delta Tb = \frac{Kb \times W2 \times 1000}{M2 \times W1} \implies M2 = \frac{Kb \times W2 \times 1000}{\Delta Tb \times W1}$ From Depression of Freezing Point: $\Delta Tf = \frac{Kf \times W2 \times 1000}{M2 \times W1} \implies M2 = \frac{Kf \times W2 \times 1000}{\Delta Tf \times W1}$ From Osmotic Pressure: $\Pi = \frac{W2 R T}{M2 V} \implies M2 = \frac{W2 R T}{\Pi V}$ \nThus, by measuring any of these properties for a solution of known concentration, the molar mass ($M2$) of the solute can be accurately determined.

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Definition of Colligative Properties
Properties of dilute solutions that depend only upon the number of solute particles (molecules or ions) relative to the total number of particles present in the solution, and not on the chemical nature or identity of the solute, are called colligative properties (derived from the Latin word colligare meaning 'to bind together'). Four Major Colligative Properties Relative Lowering of Vapour Pressure: The lowering of vapour pressure depends on the mole fraction of the non-volatile solute particles. Elevation of Boiling Point: The increase in the boiling point of a solvent due to the addition of a non-volatile solute. Depression of Freezing Point: The lowering of the freezing point of a solvent upon the addition of a non-volatile solute. Osmotic Pressure: The excess hydrostatic pressure that must be applied to prevent the passage of solvent molecules into the solution through a semipermeable membrane. Determination of Molar Mass Using Colligative Properties
All colligative properties are directly or inversely proportional to the number of moles of solute, which allows chemists to calculate the molar mass of unknown non-volatile solutes. From Relative Lowering of Vapour Pressure: $\frac{p1^0 - p1}{p1^0} = \frac{W2 M1}{M2 W1}$, where $M2$ can be calculated. From Elevation of Boiling Point: $\Delta Tb = \frac{Kb 	imes W2 	imes 1000}{M2 	imes W1} \implies M2 = \frac{Kb 	imes W2 	imes 1000}{\Delta Tb 	imes W1}$ From Depression of Freezing Point: $\Delta Tf = \frac{Kf 	imes W2 	imes 1000}{M2 	imes W1} \implies M2 = \frac{Kf 	imes W2 	imes 1000}{\Delta Tf 	imes W1}$ From Osmotic Pressure: $\Pi = \frac{W2 R T}{M2 V} \implies M2 = \frac{W2 R T}{\Pi V}$ 
Thus, by measuring any of these properties for a solution of known concentration, the molar mass ($M2$) of the solute can be accurately determined.

NCERT · Class 12 · Chemistry · SolutionsWhat is meant by Colligative properties? Name the four colligative properties and explain how they are used for the determination of molar mass of non-volatile solutes.

Four Major Colligative Properties

Determination of Molar Mass Using Colligative Properties\nAll colligative properties are directly or inversely proportional to the number of moles of solute, which allows chemists to calculate the molar mass of unknown non-volatile solutes.