Solubility Product Principle

• Solubility


  The maximum amount of a species that can dissolve in a given volume of solvent
• Soluble


  If more than 1 g of a species dissolves in 100 g of water
• Slightly soluble


  If between 0.1 g and 1 g of a species dissolves in 100g of water
• Insoluble


  If less than 0.1 g of a species dissolves in 100g of water
• Dissolution


  The process of dissolving
• Precipitation


  The opposite of dissolving
• Saturation of solutions


  • Unsaturated
  • Saturated
  • Supersaturated
• Solubility equilibrium


  1. Dissolution

  2. Precipitation
• Solubility equilibria


  • Equilibrium concentrations of products and reactants can be represented using an equilibrium constant
  • Equilibrium always tends towards a certain position
  • At equilibrium, the rate of forward reaction equals the rate of backward reaction
  • At equilibrium, the concentrations of products and reactants don't change
• Solubility product


  The equilibrium constant for the dissolution of an ionic species in a solubility equilibrium
• The solubility product gives an indication of solubility - the higher the value, the greater the solubility
• The solubility product can be used to quantitatively calculate a slightly soluble species' solubility
• The solubility product can be used to predict whether a salt will precipitate or not if equilibrium conditions change
• Common ion


  An ion found in two different compounds
• Common ion effect


  Ionic species are less soluble in solutions containing a common ion
• Calculating solubility product (Ksp)

  1. Write balanced equation

  2. Calculate concentration of ions using given information

  3. Plug into Ksp equation and solve
• Simon Baron Cohen: 'Empathy is like a universal solvent, any problem immersed in empathy becomes soluble.'