Solubility

• Solubility


  The amount of solute that will dissolve in a given amount of solvent
• Types of solutions


  • Unsaturated solution
  • Saturated solution
  • Supersaturated solution
• Unsaturated solution


  More solute dissolves
• Saturated solution


  No more solute dissolves
• Supersaturated solution


  Becomes unstable, crystals form
• Principle of solubility


  • Like dissolves like - pertains to the similarity in the polarity of substances
• Temperature

  Solubility increases of most solids dissolved in water
• Higher temperatures increase the vibration or kinetic energy of the solute molecules
• Temperature increases


  Solubility of gases decreases
• Pressure


  Only affects the solubility of gases - as pressure increases, solubility of gases increases, and as pressure decreases, solubility decreases
• Colligative properties


  Physical changes that result from adding solute to a solvent, depend only on the number of solute particles present, not on the identity of the solute particles
• Colligative properties


  • Vapor pressure lowering
  • Freezing point depression
  • Boiling point elevation
  • Osmotic pressure
• Vapor pressure lowering


  The vapor pressure of a solution with a nonvolatile solute is always lower than that of the pure solvent
• The relationship between the vapor pressure of the solution and the vapor pressure of the solvent depends on the concentration of the solute in the solution
• Vapor pressure


  The pressure exerted by the vapor particles on the liquid at equilibrium
• Higher concentrations of non-volatile solutes make it harder for solvent to escape to the vapor phase, therefore the vapor pressure of a solution is lower than that of the pure solvent
• Raoult's Law


  The vapor pressure of a solution, PA, is equal to the mole fraction of the solvent, Xa times the vapor pressure of the pure solvent, PA
• Boiling point elevation


  The change in boiling point is proportional to the molality of the solution
• Freezing point depression


  The change in freezing point can be found similarly to boiling point elevation
• Osmosis


  A process through which a solvent flows through a semipermeable membrane from a less concentrated solution to a more concentrated one
• Osmotic pressure


  The amount of pressure required to stop the osmosis
• Types of osmotic concentration

  • Hypotonic
  • Isotonic
  • Hypertonic
• Hypotonic


  The solute concentration is lower outside of the cell than that inside the cell, causing the cell to take in water and swell
• Isotonic


  The water outside of the cell has an EQUAL amount of salt as the water INSIDE of the cell, causing no change in cell size
• Hypertonic


  The solute concentration is higher outside than that inside the cell, causing it to shrivel and shrink
• osmosis is also known as water diffusion
• higher temperature increases the kinetic energy/vibration of solute molecule