For the teacher’s introductory demonstration:

• dropper
• water and alcohol, several drops of each

Each group needs:

• three 250-ml beakers
• thermometer
• glass stirring rod
• hot plate
• pH meter; alternatively, use pH paper
• 50-ml graduated cylinder
• pipette
• 4 test tubes with caps
• penny
• 50 g olive oil
• 6.7 g potassium hydroxide (KOH)
• 50 ml of 5% triethanolamine
• 1 drop of phenolphthalein
• 5% oleic acid in ethanol solution, 5 to 10 drops
• 100 ml deionized (DI) water
• 1 ml tap water
• 1 ml each of acidic water, hard water and salt water; prepared as follows (plenty for the entire class):
• acidic water: 700 ml of distilled water + 300 ml of vinegar
• hard water: 1 liter of distilled water + 70 grams of CaCl₂ (calcium chloride)
• salt water/seawater: 1 liter of distilled water + 62 grams of NaCl (salt)
• 12 x 12-inch (~30 x 30-cm) polypropylene sheet, such as cut from a 24 x 36-inch (61 x 91-cm) Twinwall Plastic Sheet for $8.61 at Home Depot
• a way to label beakers
• drain or bucket for viscosity test
• stopwatch, or other timer
• (optional) fragrance to add to homemade soap, such as essential oils
• Soap vs. Shampoo Lab Worksheet, one per student
• Soap vs. Shampoo Post-Lab Quiz, one per student

Note: Chemicals are available from chemical supply vendors like Flinn Scientific, as well as Amazon.com.