1. Lecture 193/12/07

2. Sample (100 mL – 0.1 M) Titrant (0.2 M) Initial pH pH at equivalence point pH at 2X equivalence point X-axis at equivalence point Strong acid Strong base Weak acid Strong base Strong acid Weak base Strong acid Give examples of: Strong acid Strong base Weak acid Weak base

3. Which solution is a buffer? Explain. a) A mixture of sodium acetate to acetic acid b) A mixture of sodium nitrate and nitric acid

4. In lab, you titrate a 25-mL sample of HCN with 0.075 M NaOH. If it takes 37.5 mL to reach the equivalence point, what is the concentration of the HCN?

5. Which of these combinations would be the best to buffer the pH at approximately 9? a) CH 3 COOH (K a = 1.8 x 10 -5 ) / NaCH 3 COO b) HCl (K a = very large) / NaCl c) NH 3 (K b = 1.8 x 10 -5 ) / NH 4 +

6. Put in order high pH to low (0.1 M solutions) KNO 3 CaO HBr C 6 H 5 COOH NaH

7. Sketch all the possible types of acid/base titrations curves