1. Special Conditions for Buffers

2. Special Conditions [weak acid] = [weak base] Then pH = pKa
At equivalence point( moles H+ = moles OH-)
Weak acid plus a strong base (1 liter)
HA + OH-  H2O + A-
.1 mol .1 mol mol
-.1 mol mol mol
0 mol mol mol
A- is weak base, therefore you will need to solve a weak base problem.
A- + H2O  HA + OH-

3. Titration
Titration: A method of determining the concentration of a solution. Titration Curve: Shows pH change Equivalence point: moles acid = moles base End point: when the indicator changes color

4. Titration Curves
Strong Acid with a Strong Base HCl + NaOH  H2O + NaCl Overall solution at eq point has a pH of 7 pH 7
Eq point
Vol SB

5. Titration of a Weak Acid with Strong Base
Why is the pH Above 7? HA + OH-  H2O + A- We made a weak base. Weak base dissociates to make a basic solution. A- + H2O  HA + OH- pH
Eq point 7
Vol SB

6. Titration of WB with a SA
Why is pH below 7? A- + H+  HA We made a weak acid. So then the weak acid will dissociate, making the solution acidic. HA  H+ + A- pH 7
Eq point
Vol SA