Lesson 4: Neutralization Reactions
Objectives: The student will learn and apply science process skills.
The student will observe and identify neutralization reactions.
Standards Addressed by lesson: Standards
Concept: This lesson is designed to give students an idea of neutralization reactions and their real-world applications.
Exploration: The Structure of Aspirin will provide students insight into the structure of aspirin, which they will apply to reactions seen later in the lesson.
Data Collection: In small groups of 3-4 students the students will then hypothesize how the components of the aspirin molecule affect its reactivity and use as medication.
Concept Introduction: As a class, visit Neutralization Reactions. This website will serve as an overview and introduction to neutralization. Students will read the aspirin information article, Aspirin. 2 After they are done reading, they will answer questions based upon the article, Aspirin article-What did you learn?. As a class, discuss their answers and assess them for misconceptions, referring to Aspirin article-What did you learn? ANSWERS.
Application Activity: In doing this lab, Simulated Stomach, students should find that when the three types of aspirin are dropped in water, the buffered aspirin may quickly begin to bubble and disintegrate. The enteric aspirin will eventually begin to disintegrate in the water, but it takes a very long time for the coating to dissolve and will not likely happen during a class period. In the acidic solution, the buffered aspirin very quickly begins to bubble vigorously. The regular aspirin disintegrates in the acidic solution just the way it does in water. The enteric aspirin can soak in the acidic solution for several hours without dissolving. In the basic baking soda solution, all three types of aspirin will dissolve relatively quickly, although the enteric aspirin still takes longer than the other two. In these solutions, vigorous bubbling should be seen in all cases as the acidic proton on aspirin reacts with the bicarbonate ion to produce carbonic acid, which breaks down to carbon dioxide gas and water. 1
History: The aspirin article provides some history of the production and uses of aspirin.
Websites:
References:
1. American Association for the Advancement of Science. "Acid Stomach." Science Netlinks. 7 Aug 2003. http://www.sciencenetlinks.com/lessons.cfm?Grade=9-12&BenchmarkID=8&DocID=0
2. Marsala, Gail. "Aspirin." American Chemical Society.2006. http://www.chemistry.org/portal/a/c/s/1/acsdisplay.html?DOC=vc2%5C1rp%5Crp1_aspirin.html
3.Wilbraham, A.C., et.al. “Chapter 19.4: Neutralization Reactions.” Chemistry. Prentice Hall: 2005. 612-623.