Chemistry: Solutions and Their Properties

Concentration

• Measures the amount of solute dissolved in a given amount of solvent
• Expressed in terms of:
  • Molarity (M): moles of solute per liter of solution (mol/L)
  • Molality (m): moles of solute per kilogram of solvent (mol/kg)
  • Mass percentage: mass of solute per 100 grams of solution
  • Volume percentage: volume of solute per 100 mL of solution

Boiling Point Elevation

• The boiling point of a solution is higher than that of the pure solvent
• The amount of boiling point elevation depends on:
  • The concentration of the solution
  • The molecular weight of the solute
  • The boiling point of the pure solvent
• Boiling point elevation (ΔTb) is directly proportional to the molality of the solution

Osmosis

• The movement of solvent molecules from an area of high concentration to an area of low concentration through a selectively permeable membrane
• Types of osmosis:
  • Isotonic: equal concentration of solute on both sides of the membrane
  • Hypotonic: lower concentration of solute on one side of the membrane
  • Hypertonic: higher concentration of solute on one side of the membrane

Freezing Point Depression

• The freezing point of a solution is lower than that of the pure solvent
• The amount of freezing point depression depends on:
  • The concentration of the solution
  • The molecular weight of the solute
  • The freezing point of the pure solvent
• Freezing point depression (ΔTf) is directly proportional to the molality of the solution

Molarity and Molality

• Molarity (M): moles of solute per liter of solution (mol/L)
• Molality (m): moles of solute per kilogram of solvent (mol/kg)
• Molarity and molality are related by the density of the solution

Heat Curves

• A graph of the temperature of a solution versus time as it freezes or boils
• Heat curves can be used to:
  • Determine the freezing point of a solution
  • Determine the boiling point of a solution
  • Identify the melting point of a pure substance

Solubility

• The maximum amount of solute that can dissolve in a given amount of solvent at a specific temperature
• Factors affecting solubility:
  • Temperature: solubility often increases with increasing temperature
  • Pressure: solubility often increases with increasing pressure
  • Polarity: solutes dissolve in solvents with similar polarity

Test your understanding of solution chemistry, including concentration, boiling point elevation, osmosis, freezing point depression, and solubility. This quiz covers the fundamental concepts and formulas used to describe the properties of solutions.