15.1-15.2

• A buffer solution is composed of what?

  A weak acid and a weak conjugate base
• EX: HF/ NaF (Weak acid and conjugate weak base)

  HC2H3O2/Na(C2H3O2)
• pOH goes down, pH goes up
• Since there is more acid than base, the pH<pKa
• If there is more base than acid, the pH>pKa
• pKa + pKb = 14
• pKa + log(B/A)
• pKa + log(salt/acid)
• a

  
• a

  
• Larger Ka more acidic, lowers pH
• When protons are added to a buffered solution of a weak acid with its conjugate base, the pH will remain approximately constant.
• Must contain a weak base in a conjugate acid or vice versa in order to use the Henderson-Hasselbalch equation.
• Assume that the equailivrium concentrations of A- and HA are approximately equal to their initial concentrations.