Chem 2 Chp 15

• • Strongs become -> nons (does not affect pH)
  • weaks become -> weaks (it will affect pH)
  • Kw = Ka * Kb (Kw= 1.0*10^-14) or Kw = [H+] [OH-]
• • buffer: a solution that resists pH change by neutralizing added acid / base
  • must contain significant amount of weak acid and its conjugate base
  • if add strong base -> pH goes up
  • if ass strong acid -> pH goes down
• • calculating pH of a buffer
  • BAA chart : can use mol
  • H - H equation
• buffers are most effective when [acid] = [base] or when [acid] and [base] are high
• • solubility product constant (Ksp): measure of solubility of a compound
  • rule #1 ions: Li+ , Na+ , K+ , Cs+ , Rb+, NH4+, NO-3, ClO-4, C2H3O-2
  • do not include them in ksp calculation
• • breaks in to 2 -> ksp = s^2
  • breaks into 3 -> ksp = 4s^3
  • breaks into 4 -> ksp = 27s^4
  • breaks into 5 -> ksp = 108s^5
• relative solubility: can only compare Ksp if they break into the same amount of pieces
• • Q < Ksp : precipitate will not form
  • Q = Ksp : saturated solution ; more solid won't dissolve
  • Q > Ksp : precipitate will form