1. Buffers: A Microscopic View CHM 102 Sinex Type your name in the textbox below: To advance slide: click outside of the textbox!

2. HAA-A- H+H+ + Here is the equilibrium that controls the buffer’s pH. What are the two major components of the buffer? answer the weak acid (protonated form) the salt or acid anion, which acts as a weak base (deprotonated form) Give an example:

3. HAA-A- add acidadd base H+H+ OH - HAA-A- A - /HA = Count and enter: Playing the Le Chatelier Game with a Equilibrium Reaction

4. HAA-A- add more acid H+H+ HAA-A- A - /HA = Count and enter:

5. HAA-A- Move on HAA-A- A - /HA = Count and enter: Return to add base

6. HAA-A- add more base OH - HAA-A- A - /HA = Count and enter:

7. HAA-A- Move on HAA-A- A - /HA = Count and enter: Return to add acid

8. HAA-A- H+H+ + salt/acid ratio So change the salt/acid ratio and the (H + ) responds!!!

9. Add a small amount of acid to buffer: HAA-A- H+H+ + A-A- H+H+ + OH - HA + A-A- H2OH2O + Predict the products answers How does the salt/acid ratio change for each addition above? Add a small amount of base to buffer:

10. How does the salt/acid ratio change? For a small amount of acid to buffer: For a small amount of base to buffer:

11. Is there a limit to how much acid or base can be added to a buffer and still have it buffer? HINT: Why do we say a small amount of acid or base? Look at the reactions… To the reactions…

12. Why doesn’t a solution of HCl and NaCl buffer? Hint!!! How does the chloride ion function as a base?

13. What happens to the buffer pH if it is diluted? What is the salt-to-acid ratio? A - /HA =

14. Which box will be the best buffer? HAA-A- H+H+ Explain your choice

15. Which box will not the buffer? HAA-A- H+H+ Explain your choice

16. Which box has the highest pH? HAA-A- H+H+ Explain your choice

17. If you are done… Go to File and select Print or Hit the print button icon on the menu bar. This will print out in handout format with 3 pages and will include all your answers. Reward