1. What effect does dilution of an acid or base have on the pH of the solution?

2. On page 4 of your notebook, write predictions in complete sentences…
What effect does dilution of an acid or base have on the pH of the solution?
On page 4 of your notebook, write predictions in complete sentences…
Will the pH of an acid increase, decrease, or remain the same if you add water to it?
Will the pH of a base increase, decrease, or remain the same if you add water to it?
Will the pH of water increase, decrease, or remain the same if you add water to it?

3. What effect does dilution of an acid or base have on the pH of the solution?
Play around with the sim a little to see how it works. Watch the video introduction to the sim HERE. Come up with a procedure to answer the research question: “What effect does dilution of an acid or base have on the pH of the solution?”
Use these guiding questions in your investigation. Write responses to these questions on page 4 of your notebook. Use complete sentences.
What is the pH of water?
Can you turn an acidic solution basic by diluting the solution?
Can you turn a basic solution acidic by diluting the solution?
When an acid or base is diluted, what pH value does it move towards?
What effect does dilution of an acid have on the pH of the solution?
What effect does dilution of a base have on the pH of the solution?

4. Please answer these questions on page 4 of your notebook
What effect does dilution of an acid or base have on the pH of the solution?
Please answer these questions on page 4 of your notebook
What did you learn from this exercise?
What effect does dilution of an acid or base have on the pH of the solution?
Review your predictions from earlier… Were you right or wrong with any of your predictions?

5. Do this investigation on page 5 of your notebook.
On the molecular level, what is the difference between acids and bases?
Do this investigation on page 5 of your notebook.

6. Product of [H3O+] x [OH-]
On the molecular level, what is the difference between acids and bases?
Use THIS sim (click on “Micro”). Watch THIS video to get an overview of the activity.
Create a table in your notebook like the one below… Make enough rows to test 4 chemicals and 4 dilutions:
Chemical pH
H3O+ Count
OH- Count
Product of [H3O+] x [OH-]
Chem A
Dilute Chem A

7. Choose 1 chemical (coffee, for example).
On the molecular level, what is the difference between acids and bases?
Choose 1 chemical (coffee, for example).
Write down the pH, the [H3O+] and the [OH-]... Remember: [brackets] represent “concentration.”
Multiply those numbers together. Write down your data.
Make a dilute solution of your chemical. Repeat steps 2 and 3.
Repeat this process for a total of 4 different chemicals and their dilutions.

8. What is the product of [H3O+] x [OH-]
On the molecular level, what is the difference between acids and bases?
Answer these prompts:
Describe the difference between an acid and a base on the molecular level.
What is the product of [H3O+] x [OH-]
What happens to pH as [H3O+] increases? Decreases?
What happens to pH as [OH-] increases? Decreases?
Add a ninth row to your table… Repeat the process for pure water.

9. Product of [H3O+] x [OH-]
Example
On the molecular level, what is the difference between acids and bases?
Chemical pH
H3O+ Count
OH- Count
Product of [H3O+] x [OH-]
Coffee
5.00
1.0 x 10-5
1.0 x 10-9
Dilute Coffee
5.36
4.4 x 10-6
2.3 x 10-9
Blood
Dilute blood

10. pH Scale: qualitative learning goals
Determine if a solution is acidic or basic using
pH b) H3O+/OH- ratio molecular size representation c) Hydronium/Hydroxide concentration
Relate liquid color to pH.
Predict if dilution and volume will increase, decrease or not change the pH
Organize a list of liquids in terms of acid or base strength in relative order with supporting evidence. 
Write the water equilibrium expression. Describe how the water equilibrium varies with pH.

11. 1. The color of a solution identifies if it is an acid, base, or neutral solution.
B color of solution is not an identifying caharacteristic. Show sim: the left is milk, then blood, then a soup
True B. False C. red is acid & clear is base

12. 2. Which solution is basic?
Correct answer D (B and C) A milk, B blood C. custom at pH =12
A B C
D. More than one E. None

13. 3. Which solution is acidic?
Correct answer is C, but they may argue E A. Custom pH =13 B. water pH =7 C. vomit pH=2
A B C
D. More than one E. Difficult to tell

14. 4. Which solution is basic?
This replaced the representation on the hidden slide #5 from the legacy sim
Correct answer B A. pH =7 B. pH = C. pH =2.37
A B C
D. More than one E. None

15. 5. Which solution is acidic?
Correct answer D (A and B) A. Coffee pH =5 B. soda pop pH =2.5 C. custom pH =13,
A B C
D. More than one E. None

16. 6. How will adding water effect the pH?
Increase the pH
Decrease the pH
No pH change
A more water lessens the acidity, so pH goes up

17. A: more water lessens the acidity, so pH goes up
Use sim to show this

18. 7. How will equal amount of water effect the pH?
Increase the pH
Decrease the pH
The pH will be cut in half
No pH change
B: more water lessens the basicity , so pH goes down, but not by 2 (log scale)

19. B: more water lessens the basicity , so pH goes down, from 10 to 9
B: more water lessens the basicity , so pH goes down, from 10 to 9.7, but not by 2 (log scale)
Use sim to show this

20. 8. What is the order from most acidic to most basic?
A B C
A B C
A C B
B A C
C B A
C A B
Correct answer is A A milk, B blood C. custom at pH =12

21. 9. What is the order from most acidic to most basic?
A B C
A C B
B A C
C B A
C A B
Correct answer C A. Water pH =7 B. pH =13 C. soda pop pH =2.5
A B C

22. 10. If spit has a pH = 7.4, what does that tell you about the water equilibrium? 2H2O  OH- + H3O+
Something was added that made the equilibrium shift left
Something was added that made the equilibrium shift right
pH has nothing to do with the water equilibrium A

23. Answer to 10 Since the pH is not 7, then something was added to make the equilibrium shift left. For example, if NaOH was added to water, OH- is immediately in the solution and some of it will react with the H3O+ , so the pH (which is inversely related to [H3O+ ]), goes up. If something like HCl were added there would be more H3O+ , which would also cause a shift left, but there would be less OH- , (which is directly related to pH), so the pH is less than 7.