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Activity 4. How Does Soap Work?. Objectives: SWBAT . Identify polar and non-polar materials Explain the behavior of a mixture of two immiscible liquids Explain the effect of a surfactant on such a mixture. Drill:. What is surface tension?. Homework:. None. Chapter Challenge.
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Activity 4 How Does Soap Work?
Objectives: SWBAT • Identify polar and non-polar materials • Explain the behavior of a mixture of two immiscible liquids • Explain the effect of a surfactant on such a mixture
Drill: • What is surface tension?
Homework: • None
Chapter Challenge • Create a procedure to make a soap from natural products that can be sold at local stores.
What Do You See? • Look at the cartoon on page 779 and be prepared to discuss what you see.
What do you think? Soap molecules have both polar and non-polar parts that allow them to dissolve both hydrophilic and hydrophobic substances. • How can molecules of soap dissolve both hydrophilic and hydrophobic substances?
Investigate • Pages 779 – 783 • Completeness and neatness of work makes a difference. Answer all questions in complete sentences.
Chem Talk • Action of Soap and Water • Micelles • An aggregation of molecules that have a polar or ionic end and a non-polar end such that in aqueous solution the polar ends will be outside the aggregate attracted to the water and the non-polar ends will be inside the aggregate away from the water
Chem talk • Surface Tension • The result of intermolecular attraction force that causes the liquid to minimize its surface area
Chem Talk • Soap Decreases Surface Tension • Decreases surface tension and allows bubble to be formed or allows needle to drop • Minimizes hydrophobic interaction between water and dirt or oil.
What do You Think Now? At the beginning of this activity you were asked • How can molecules of soap dissolve both hydrophilic and hydrophobic substances? • Review your answer. • How are soap molecules arranged inside a hydrophilic substance, such as water? • How are soap molecules arranged inside a hydrophobic substance, such as kerosene?
Chem Essential Questions • What does it mean? • Macro • Describe what happened when you touched a soapy finger to the water with a sewing needle floating on top
Chem Essential Questions • What does it mean? • Nano • On a molecular level, describe what happened when the soap was added to the water.
Chem Essential Questions • What does it mean? • Symbolic • Draw a diagram of soap molecules dissolved in water
Chem Essential Questions • How do you know? • What evidence do you have that a strong attraction exists between water molecules?
Chem Essential Questions • Why do you believe? • Cleaning clothes requires the use of soap and water. Why can water alone not do the job of cleaning clothes?
Chem Essential Questions • Why should you care? • An understanding of the interaction among water molecules or water molecules and other polar molecules will be required in order to produce a soap that has desirable properties. Creating a soap requires you to be aware of its molecular structure. What molecular structure will you require for your new soap?
Homework • Chem to Go • pp 787 • Questions 1-8