Principles of Reactivity: Other Aspects of Aqueous Equilibria Chapter 18 || v Principles of Reactivity: Other Aspects of Aqueous Equilibria

Common Ion Effect •The limiting of the ionization of an acid or base by the presence of a significant concentration of its conjugate The extent to which the acid can ionize is affected, affecting pH

Buffer solutions •Buffer solutions cause resistance to change in pH when a strong acid or base is added. •Prepared from a conjugate acid-base pair •pH= pK a+ log([conjugate base]/[acid]) •Requirements: •the acid and base must not react with one another •Acids capable of reacting with OH- ions •base that can consume added H3O+ ions Dank memes | v

Acid base titrations The equivalence point is the midpoint of the vertical segment of the pH vs volume of titrant curve. pH at the equivalence point in a strong acid/strong base is 7 More memes→ <--- Actual science stuff

Solubility of salts Precipitation reactions have a product which is a water-insoluble compound Equilibrium constant reflects the solubility of a compound referred to as its solubility product constant Ksp The solubility of a salt is the amount present in some volume of saturated solution. The Ksp is an equilibrium constant (SALT)

Precipitation Reactions The Q (reaction quotient) and K (equilibrium constant) may or may not be at equilibrium -If Q=Ksp the solution is saturated -If Q<Ksp the solution is not saturated -If Q>Ksp the solution is over(super) saturated (precipitation→)

Solubility and complex ions Metal ions exist in aqueous solutions as complex ions Equilibrium constant for formation of complex ions is called formation constant, Kform Knet=KspKform

Henderson Hasselbalch pH=pKa+log(base/acid) Determines the pH range of a buffered solution Uses the acid dissipation constant by: Ka=[H+][A-]/[HA] Rearranged as: [H+]=Ka[HA]/[A-] Then take the -log of the expression and rearrange in order to make each figure positive

Assignment: Page 850-854: 7, 8, 25, 29, 33, 53