1. Activity 43 Follow-up
Flocculate- To add chemicals into water to mix with and pull together the contaminants into large clumps
Sediment- The clumps formed by flocculation that sink to the bottom of the water
Sedimentation- The process of letting the clumps formed by flocculation sink to the bottom of the water

2. Cleaning the Water at a Water-Treatment Plant

3. Where does our water come from?

4. The Water Authority delivers water to the 23 retail water agencies that in turn deliver water to their retail customers.

5. Existing Water Resources Within SDCWA

7. Activity 43 Analysis
What do you know about the source of your community’s drinking water?
Comes from Northern California via the California Aqueduct and the Colorado River Aqueduct

8. Do you think there are other communities that might contribute contaminants to your water source or get their water from the same source?
Most of our water supply is surface water which is supplied from many rivers and streams
See earlier map

9. Look at the map below, and find the Great Lakes
Look at the map below, and find the Great Lakes. Why do you think the United States and Canada cooperate to keep the Great Lakes clean?
The Great Lakes are bordered by both the United States and Canada.
Both use water from the lakes
Both have communities and industries located on the lakes
For these reasons, both want to be able to get clean water from the lakes and work together to be sure that neither is polluting them

10. The reading describes two chemicals that are used to remove contaminants from drinking water. What are these chemicals, and what is the purpose of each one?
Aluminum sulfate or other chemicals are used to coagulate and remove dirt and other contaminants
Chlorine is used to kill biological contaminants
Which water source would you expect to be more likely to become contaminated by pesticides---surface water or groundwater? Explain why you think that.
Surface water is more open to the environment
People can dump things into it and cause contamination

11. Title: Investigating Solutions of Acids and Bases
Activity 46
Title: Investigating Solutions of Acids and Bases

12. What do you know about acids and bases?
Acidic or basic water outside of a specific pH range violates federal standards for drinking water.
Higher pH = more basic
Lower pH = more acidic
Neutral pH = 7
Federal water-quality standards require testing for pH, because water with a high or low pH can corrode pipes and release harmful metals from the pipes into drinking water.

13. Read C-82
Problem: How can solutions be tested to identify them as acidic, basic, or neutral?
Initial Thoughts/Hypothesis:

14. In this activity you will…
Work with several acid-base indicators:
Universal Indicator
Phenolphthalein
pH paper
An indicator is a substance used to detect the presence of specific kinds of chemicals.

15. Background: Indicator Acid Base Neutral Phenolphthalein Colorless
Bright Pink
Universal Indicator
Red or Pink
Blue
Green
pH Paper
Red or Orange-Red
Blue or Purple
Yellow-Green

16. Procedure: Follow procedure on pgs. C-83 to C-85
A data table will be provided for you. Discuss procedure step #2 with your group. Don’t write your plan in your notebook.
DO NOT GLUE YOUR TABLES IN YET!

17. Data/Observation: Table 1: Indicator Test Liquid Indicator
Phenolphthalein
Universal Indicator
pH paper
Water from the sink
Hydrochloric Acid
Potassium Hydroxide
Rubbing Alcohol
Milk
Lemon Juice
Household Ammonia
Baking Soda in Water
Sprite
White Vinegar

18. You have 3 substances to test with 3 different indicators
You have 3 substances to test with 3 different indicators. How will you set up your tray?
Hydrochloric Acid (HCl)
Potassium Hydroxide (KOH)
Water from the Sink
Phen
HCl
KOH
H2O
U.I. pH
Phen
HCl
KOH
H2O
U.I. pH
HCl
KOH
H2O
Phen
U.I. pH
Phenolphthalein
Universal Indicator
pH Paper

19. Demo: Water Hydrochloric Acid (HCl) Potassium Hydroxide (KOH)
Lemon juice
Test the other solutions and compare.
Neutral
Acidic
Basic
Acidic

20. Part B
What do you think will happen to the pH of the acid or base if you dilute it with water?
In part B is a serial dilution of HCl and KOH
Copy the results form the teacher

21. Table 2: Serial Dilution of 1% HCl Solution

22. Table 3: Serial Dilution of 1% KOH Solution