1. Acids and Bases

2. TITLE The effect of an indicator on determining the pH level of various substances.

3. PROBLEM STATEMENT How can a pH indicator determine the pH level of substances?

4. HYPOTHESIS If an indicator is used, then the acidity and alkalinity(base) can be determined, because various colors will be observed indicating the pH level of the substance due to the number of hydrogen ions (H + ).

5. VARIABLES  Independent variable-  Dependent variable-  Constant-

6. MATERIALS  Cabbage juice  12 test tubes  Test tube rack  Variety of solutions (refer to the data table)  Pipettes  Litmus paper  Apron  Goggles

7. PROCEDURES  1. Place the solutions in the test tubes.  2. Add 3-4 drops of cabbage juice to each test tube.  3. Observe and record observations on the data table.  4. Use the litmus paper (red and blue) to determine whether the substances are a base, an acid or neutral based on the color of the paper.  5.Record your observations.

8. DATA TABLE SubstanceHypothesispH Level Acid or Base Color Color of Litmus Paper 1.Vinegar 2.Baking Soda 3.Gingerale 4.Antacid 5.Orange Juice 6.Tap Water 7.Salt Water 8.All Purpose Cleaner 9.Liquid Soap 10.Ammonia 11.Milk 12.Tea

9. DATA ANALYIS  Refer to the handout  Write Questions and Answers  Answer to #6 : The numbers on the pH scale run from 0 to 14. Substances with lower pH's have much more hydrogen, or H+, than substances with higher pH's. For example:pH scale * Choose two of these to include with question #6  Vinegar, with a pH of 3, has ten times more H+ than lemon juice, with a pH of 4.  Lemon juice, with a pH of 4, has ten times more H+ than aspirin water, with a pH of 5.  Aspirin water, with a pH of 5, has ten times more H+ than milk, with a pH of 6.

10. CONCLUSION PARAGRAPH #1  Start the paragraph with the purpose of the lab. Refer to the scientific title.  What is the hypothesis?  What procedures were followed.  Include the variables and constant in this activity

11. CONCLUSION PARAGRAPH #2  Include the answers to the analysis questions.

12. CONCLUSION PARAGRAPH #3  Real-world application-Refer to the writing and naming acids and bases notes. List 3 acids and their uses. List 3 bases and their uses. What would be the result if your skin is exposed to an acid or a base?