In this activity, students make a liquid hand soap similar to commercial liquid hand soaps and compare the properties of the homemade hand soap to those of a commercial brand. Abilities of Technological Design Students implement a proposed design, measuring and mixing ingredients to make a liquid hand soap. Students evaluate completed technological designs or products with several tests.
Students describe results from the product evaluation stage of the technological design process.
The types of substances included in a mixture play an important role in determining the properties of the final mixture. The electric force is a universal force that exists between any two charged objects. The nonpolar tail of the lauryl sulfate ion is repelled by polar water molecules, while the negatively charged polar end of the lauryl sulfate ion is attracted to water. Cultural preferences determine what products scientists develop and the characteristics of the products. Some diseases and illnesses can be prevented by good personal hygiene such as handwashing with soap.