• • Liquid Solutions: Solute is a liquid, solvent is a liquid (e.g., alcohol in water).
  • Gaseous Solutions: Solute is a gas, solvent is a gas (e.g., air).

Concentration of Solutions:

• Concentration: The amount of solute dissolved in a given amount of solution.

• • Volume percentage (% v/v): Milliliters of solute per 100 milliliters of solution.
  • Molarity (M): Moles of solute per liter of solution.
  • Molality (m): Moles of solute per kilogram of solvent.
• Interconversion of Concentration Units: Calculations exist to convert between different units based on solution density and solute molar mass.

3. Colligative Properties:

• Colligative properties: Properties of a solution that depend only on the concentration of solute particles, not their identity.
• Examples:
  • Vapor pressure lowering: Solute presence lowers the solvent's vapor pressure compared to the pure solvent.
  • Boiling point elevation: The boiling point of a solution is higher than that of the pure solvent.
  • Freezing point depression: The freezing point of a solution is lower than that of the pure solvent.
  • Osmotic pressure: The pressure required to prevent the flow of solvent across a semipermeable membrane separating a solution from pure solvent.

4. Solubility:

• Solubility: The maximum amount of solute that can dissolve in a given amount of solvent at a specific temperature and pressure.
• Factors affecting solubility:
  • Nature of solute and solvent: Similar structures tend to be more soluble in each other.
  • Temperature: Generally, solubility increases with temperature.
  • Pressure: For gaseous solutes, solubility increases with pressure.

5. Ideal and Non-ideal Solutions:

• Ideal solution: A hypothetical solution that exhibits perfect colligative property behavior based solely on solute concentration.
• Non-ideal solution: Real-world solutions that deviate from ideal behavior due to interactions between solute and solvent particles. These deviations can be positive or negative.

6. Applications of Solutions:

• Solutions are fundamental in various fields, including:
  • Chemistry: Separations, purification, reactions.
  • Biology: Physiological fluids, transport processes.
  • Pharmacy: Drug delivery, formulations.
  • Environmental science: Pollution control, remediation.