1. Dec 8, 2010 BellRinger Finish the rest of your interviews, you have 15 min! Objectives Practice presenting research projects in an a style similar to the science fair Predict the pH values of a variety of common substances Homework Rewrite the procedures on pg. 185 Take Cornell notes on the “Need to Know “ box on pg 188

2. An Evening with the Mathews Read Part I of the handout What do you know about acids, bases and pH?

3. What is the pH scale? The pH scale measures how acidic (proton donor) or basic (proton acceptor) a solution is.

4. Characteristics Of Acids Acids can be characterized by: 1. A sour taste. 2. It turns blue litmus paper red 3. It tastes sour. Try drinking lemon juice (citric acid)

5. Characteristics of Bases A Base is characterized by: 1. A bitter taste. (Milk of Magnesia) 2. It feels slippery. (Soapy Water) 3. It turns Red Litmus Blue.

6. Make a prediction for the pH of the substances in the room SubstancePredicted pHActual pH

7. pH Scale pH scale is a LOG scale ◦ Each pH unit represents a 10-fold difference in concentration of H + /OH - What is the difference in conc. of a solution with a pH of 3 then one with a pH of 5?

8. pH of Common Substance 14 1 x 10 -14 1 x 10 -0 0 13 1 x 10 -13 1 x 10 -1 1 12 1 x 10 -12 1 x 10 -2 2 11 1 x 10 -11 1 x 10 -3 3 10 1 x 10 -10 1 x 10 -4 4 9 1 x 10 -9 1 x 10 -5 5 8 1 x 10 -8 1 x 10 -6 6 6 1 x 10 -6 1 x 10 -8 8 5 1 x 10 -5 1 x 10 -9 9 4 1 x 10 -4 1 x 10 -10 10 3 1 x 10 -3 1 x 10 -11 11 2 1 x 10 -2 1 x 10 -12 12 1 1 x 10 -1 1 x 10 -13 13 0 1 x 10 0 1 x 10 -14 14 NaOH, 0.1 M Household bleach Household ammonia Lime water Milk of magnesia Borax Baking soda Egg white, seawater Human blood, tears Milk Saliva Rain Black coffee Banana Tomatoes Wine Cola, vinegar Lemon juice Gastric juice More basic More acidic pH [H 1+ ] [OH 1- ] pOH 7 1 x 10 -7 1 x 10 -7 7

11. Dec 9, 2010 BellRinger Draw a graph that represents your predictions for how you think pH will change for both water and the homogenate when you add an acid or a base Objectives Conduct a lab to determine the effect of buffers on maintaining pH Homework Answer the analysis questions from the lab

12. Regulating pH How does your body balance the different pH levels that it encounters? Our cells act as buffers!

13. Experiment Comparison of pH changes when acids and bases are added to living and non-living solutions Water (nonliving) Liver homogenate (living cells mashed in a blender)

14. Reminders Teams of 4 ◦ 2 will test the acid ◦ 2 will test the base You will share info to complete your chart

15. Dec 10, 2010 BellRinger What do you think are possible symptoms your body would show if the pH balance is thrown off? Objectives Develop conclusions about the results from a lab Analyze a case study about pH and regulation of homeostasis Homework ◦ Read “Behavior and Homeostasis” p. 239-241 (Biology TB). ◦ Write a paragraph about the benefits and drawbacks of endothermic and ectothermic temperature regulation.

16. Results What does this graph tell us?

17. The Mathews Let’s see what they are up to today… Read Part II

22. What happened to molly? Read part III

26. Read part IV

27. Read part V