1. Neutralization of Acids and Bases

2. Titrations Standard Solution Sample Solutio n Burett e Primary Standard with a precisely known [ ] Unknown [ ] Sample Solution Known [ ] Standard Solution 1st titration 2nd titration

3. In general, a titration involves the addition of either a strong acid, strong base or both (must go to completion) as follows: ACID + BASE  WATER + SALT Titrations do not always yield an equivalence point with a pH of 7. Why?  The salts produced may further hydrolyze to change the equivalence to either acidic or basic

4. Choosing Indicators For Titrations will depend on the overall pH of the salt produced

5. Strong Acids and Strong Base Titrations Example: HCl (strong acid) and NaOH (strong base) Formula Equation:__________________________________ Complete Ionic Equation: ____________________________ Net Ionic Equation:__________________________________ pH at equivalence point: _____________________________ Possible Indicators:__________________________________

6. Titration Curve for Strong Acid & Strong Base pH of sample solution is very low  SA Base is the standard solution being added

7. Strong Acid & Strong Base 1 4 3 2

8. How are the pH’s calculated at the various stages? Eg. 40.0 mL of 0.100 M HCl is titrated with 0.100 M NaOH. 1 The initial acid concentration? 2 NaOH is added (eg. 30.0 mL) but acid is in excess? 3 Equivalence point? 4 Base is in excess (eg. 50.0 mL added)?

9. Example: CH 3 COOH (weak acid) and NaOH (strong base) Formula Equation:__________________________________ Complete Ionic Equation: ____________________________ Net Ionic Equation:__________________________________ pH at equivalence point: _____________________________ Possible Indicators:__________________________________ Weak Acids and Strong Base Titrations

10. Weak Acid & Strong Base pH starts higher as CH 3 COOH is a weaker acid E.P > 7

11. Weak Base and Strong Acid Titrations Example: NH 3 (weak base) and HCl (strong acid) Formula Equation:__________________________________ Complete Ionic Equation: ____________________________ Net Ionic Equation:__________________________________ pH at equivalence point: _____________________________ Possible Indicators:__________________________________

12. Weak Base & Strong Acid Standard Acid is added Sample of Strong Base E.P < 7

13. Three types of Titrations:

14. Choosing an Indicator:

15. Monoprotic Acids When the mole ratio of acid to bases is 1:1, then they will require equal volumes to reach equivalence point Acid and Base strength is irrelevant Example: A strong acid requires an equal volume of weak base to reach equivalence point if they each have a coefficient of 1

16. Polyprotic Acids When an acid releases more than one proton, ie. H 2 SO 4, then they will require twice the volume of base to reach equivalence point

17. Titration of a polyprotic acid: one equivalence point per acidic hydrogen