Terms Solute Substance that has been dissolved in a liquid Solvent the solution (liquid or gas) part of the solute concentration Dissolves the solute Solubility The ability of a substance (solute) to dissolve Soluble – substance will completely dissolve Partially Soluble – substance will dissolve but there will be some precipitate left Insoluble – will dissolve but the amount that dissolves is very small and almost ALL the substance precipitates.

Solubility When the solid is first put into the water, the rate of dissolving is high. There is lots of room in the solution for ions Rate of forward reaction is high Dissolving After time some of these free ions will collide and go back towards the solid Rate of reverse reaction increases This process is called precipitation

Solubility Solubility Equilibrium exists when The rate of dissolving = The rate of precipitation Forward Reaction = Reverse Reaction Only look at partially soluble and insoluble solids Ksp Equilibrium constant for an ionic substance dissolving in water Solubility product constant Molar solubility Ability of a substance (solute) to dissolve in a substance (solvent) # of moles that dissolve in 1 L

Solubility Keq = [products] [reactants] Ksp = [products] We don’t take out the solids because their concentrations are constant Example PbCl2(s)  Pb2+(aq) + 2Cl‐ (aq) Keq = [Pb 2 ] [Cl] 2 PbCl 2 Ksp = [Pb 2 ] [Cl] 2

Ionic Charges