There are three components to this lesson, outlined below. Complete the activities in order to answer the central question of this lesson: “How does understanding the chemistry of hair care, including the role of pH, help in the development of better hair care products?”
Part I: Determining the pH of shampoo samples
Using the shampoo samples given to you by your teacher, determine the pH of each of the samples. You can determine pH by using a method familiar to you, such as using pH strips or probes. Record the pH of your shampoo samples below:
Shampoo name pHPart II: Treating hair samples in solutions of varying pH Complete the following activity in your lab group and answer the questions that follow.

Procedure:
1. Obtain 4 wooden splints; 4 test dishes; 20 strands of the same type of hair; and 4 strips of tape.
2. Clean the 4 dishes in pH neutral solution and rinse thoroughly with distilled water. (Be sure to clean all glassware after each use so that the samples are not contaminated.)
3. Label the test dishes pH 2.0, pH 6.0, pH 10.0, and pH 12.0. Add 10 mL of the appropriate pH solution to each of the dishes.
4. Tape 5 strands of hair to each splint with one end fastened, and the other end free to be immersed in the test solutions. Label the ends of each splint with pH 2.0, pH 6.0, pH 10.0, and pH 12.0.
5. Put each splint into the corresponding solution. Allow the hair to be exposed for 10 minutes.
6. Remove the hair sample and rinse with distilled water. Allow the strands to air dry.
7. Grasp the ends of the pH 2.0 sample and pull gently. Record observations of the following in the data table

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