Instructions: Conduct the experiments provided before going out into the virtual field for additional research.
Part I: Answer the following questions.
Section 1: You will be testing 4 known solutions for pH levels using a standard wide-range indicator. Based off of the results obtained in the lab room, fill in the following table:
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Solution Number
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pH from Lab
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Acid, Base or Neutral?
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Solution Name (what was in the test tube?)
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Solution 1
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6
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ACID
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PURE WATER
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|
Solution 2
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1
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ACID
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LEMON JUICE
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|
Solution 3
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12
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BLEACH
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|
Solution 4
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5
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ACID
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COFFEE
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1. How many drops of wide range indicator will you use for each test, based on industry standards such as the LaMotte field test?
Section 2: Now that you understand how to read pH measurements, go out into the field to gather pH samples from 3 different lakes to take back to the lab for testing, and answer the following question:
2. What was the pH level measured at Lake 1?
3. What was the pH level measured at Lake 2?
4. What was the pH level measured at Lake 3?
5. Which two lakes have the highest levels of acidity in their water? LAKE 1 AND LAKE 3
6. Based off of the information gathered at each lake, explain why your results may have turned out this way. What environmental phenomenon is at work here?
Part II: For the following questions, provide your response in short-answer format. Use this Phase's activities and resources to assist you in answering.
7. What is pH?
8. What is a base?
9. What is an acid?
10. What does it mean if a solution has more hydrogen ions (H+)?
11. What does it mean if a solution has more hydroxide ions (OH-)?
12. What does it mean if a solution is neutral?
13. Explain the pH scale and how it is used to indicate acidic, alkaline, and neutral solutions.
14. What does it mean in terms of strength when the pH of an acid changes from 5 to 4?