Lesson 4: Solubility Equilibria

• Solubility


  Maximum amount of solute per solvent
• Solubility Equilibrium


  1. NaCl(s) -> Na+(aq) + Cl-(aq)

  2. As water evaporates, the ions will crystallize and become NaCl again
• Solubility


  The quantity of solute that can dissolve in a given quantity of solvent
• Solubility Equilibrium


  AgI (s) -> Ag+(aq) + I-(aq)
• Silver


  • Tends to not dissolve well
• Solubility


  • The solubility of a compound depends on the ions it contains
  • The higher the charge, the less soluble the compound is
  • Temperature affects solubility of solids
• Solubility


  • Bigger ions dissolve faster because of the attractive force between the electrons and the nucleus (the attractions aren't as strong since the electrons are further away from the nucleus, so it takes less energy to break apart the attraction)
  • Higher charge means harder to dissolve because the bond between the ions is stronger (higher attraction)
• For a compound with a negative slope

  It is a gas, because when temperature increases for a gas, the solubility decreases
• Salt is added in cooking because it increases the boiling point of water, so it takes less time to cook pasta
• Supersaturated


  More solute dissolved than usual at a specific temperature
• Solubility Product Constant


  A saturated solution is a type of heterogeneous equilibrium (more than one phase)
• Solubility Product Constant


  1. NaCl (s) ↔ Na+ (aq) + Cl- (aq)

  2. Ksp = [Na+] [Cl-]

  3. The higher the K the more soluble the product is
• Molar solubility

  The concentration of a saturated solution in mol/L
• Solids and liquids are not included in equilibrium constant statements
• Equilibrium concentration


  The molar solubility