Home1. Concentration Terms A. Molarity (M) Definition: Number of moles of solute present in 1 litre of solution. Formula: Where: � = Mass of solute (g) � = Molar mass of solute � = Volume of solution (mL) Important: Molarity changes with temperature because volume changes. B. Molality (m) Definition: Number of moles of solute present in 1 kg of solvent. Formula: Where: � = Mass of solvent (g) Important: Molality is independent of temperature. ⭐ Frequently asked theory question. C. Mole Fraction (x) Key Relation: 2. Solubility & Vapour Pressure A. Henry's Law Statement: The solubility of a gas in a liquid is directly proportional to its pressure. Where: � = Solubility � = Henry's constant � = Pressure B. Raoult's Law For a solution containing two volatile liquids: Where: �, � = Vapour pressures of pure liquids �, � = Mole fractions C. Ideal vs Non-Ideal Solutions Ideal Solution Non-Ideal Solution Follows Raoult's law completely Deviates from Raoult's law ΔV = 0 ΔV ≠ 0 ΔH = 0 ΔH ≠ 0 Example: Benzene + Toluene Shows positive/negative deviation 3. Colligative Properties Definition Properties that depend only on the number of solute particles, not on their nature. A. Relative Lowering of Vapour Pressure (RLVP) For dilute solutions: Where: � = Vapour pressure of pure solvent � = Vapour pressure of solution B. Elevation of Boiling Point Where: � = Ebullioscopic constant C. Depression of Freezing Point Where: � = Cryoscopic constant D. Osmotic Pressure Where: � = Molarity � = 0.0821 L atm K⁻¹ mol⁻¹ � = Temperature in Kelvin Expanded form: 4. Van't Hoff Factor (i) ★ Most Important When solute particles dissociate or associate, the number of particles changes. Formula Non-Electrolytes Do not dissociate. Examples: Urea Glucose Sucrose Strong Electrolytes NaCl MgCl₂ Al₂(SO₄)₃ Degree of Dissociation (α) Where: � = Total ions formed

1. Concentration Terms A. Molarity (M) Definition: Number of moles of solute present in 1 litre of solution. Formula: Where: � = Mass of solute (g) � = Molar mass of solute � = Volume of solution (mL) Important: Molarity changes with temperature because volume changes. B. Molality (m) Definition: Number of moles of solute present in 1 kg of solvent. Formula: Where: � = Mass of solvent (g) Important: Molality is independent of temperature. ⭐ Frequently asked theory question. C. Mole Fraction (x) Key Relation: 2. Solubility & Vapour Pressure A. Henry's Law Statement: The solubility of a gas in a liquid is directly proportional to its pressure. Where: � = Solubility � = Henry's constant � = Pressure B. Raoult's Law For a solution containing two volatile liquids: Where: �, � = Vapour pressures of pure liquids �, � = Mole fractions C. Ideal vs Non-Ideal Solutions Ideal Solution Non-Ideal Solution Follows Raoult's law completely Deviates from Raoult's law ΔV = 0 ΔV ≠ 0 ΔH = 0 ΔH ≠ 0 Example: Benzene + Toluene Shows positive/negative deviation 3. Colligative Properties Definition Properties that depend only on the number of solute particles, not on their nature. A. Relative Lowering of Vapour Pressure (RLVP) For dilute solutions: Where: � = Vapour pressure of pure solvent � = Vapour pressure of solution B. Elevation of Boiling Point Where: � = Ebullioscopic constant C. Depression of Freezing Point Where: � = Cryoscopic constant D. Osmotic Pressure Where: � = Molarity � = 0.0821 L atm K⁻¹ mol⁻¹ � = Temperature in Kelvin Expanded form: 4. Van't Hoff Factor (i) ★ Most Important When solute particles dissociate or associate, the number of particles changes. Formula Non-Electrolytes Do not dissociate. Examples: Urea Glucose Sucrose Strong Electrolytes NaCl MgCl₂ Al₂(SO₄)₃ Degree of Dissociation (α) Where: � = Total ions formed

1. Concentration Terms

A. Molarity (M)

Definition: Number of moles of solute present in 1 litre of solution.

Formula:

Where:

� = Mass of solute (g)

� = Molar mass of solute

� = Volume of solution (mL)

Important: Molarity changes with temperature because volume changes.

B. Molality (m)

Definition: Number of moles of solute present in 1 kg of solvent.

Formula:

Where:

� = Mass of solvent (g)

Important: Molality is independent of temperature.

⭐ Frequently asked theory question.

C. Mole Fraction (x)

Key Relation:

2. Solubility & Vapour Pressure

A. Henry's Law

Statement: The solubility of a gas in a liquid is directly proportional to its pressure.

Where:

� = Solubility

� = Henry's constant

� = Pressure

B. Raoult's Law

For a solution containing two volatile liquids:

Where:

�, � = Vapour pressures of pure liquids

�, � = Mole fractions

C. Ideal vs Non-Ideal Solutions

Ideal Solution

Non-Ideal Solution

Follows Raoult's law completely

Deviates from Raoult's law

ΔV = 0

ΔV ≠ 0

ΔH = 0

ΔH ≠ 0

Example: Benzene + Toluene

Shows positive/negative deviation

3. Colligative Properties

Definition

Properties that depend only on the number of solute particles, not on their nature.

A. Relative Lowering of Vapour Pressure (RLVP)

For dilute solutions:

Where:

� = Vapour pressure of pure solvent

� = Vapour pressure of solution

B. Elevation of Boiling Point

Where:

� = Ebullioscopic constant

C. Depression of Freezing Point

Where:

� = Cryoscopic constant

D. Osmotic Pressure

Where:

� = Molarity

� = 0.0821 L atm K⁻¹ mol⁻¹

� = Temperature in Kelvin

Expanded form:

4. Van't Hoff Factor (i) ★ Most Important

When solute particles dissociate or associate, the number of particles changes.

Formula

Non-Electrolytes

Do not dissociate.

Examples:

Urea

Glucose

Sucrose

Strong Electrolytes

NaCl

MgCl₂

Al₂(SO₄)₃

Degree of Dissociation (α)

Where:

� = Total ions formed