Ooeey Gooey Fun! But Can We Sell This Stuff? - Putty Experiment
Author: Michael Owen
Source: 1) stevespanglerscience.com and others- provide the directions for making the putty like material; 2) Instructions for interpretation of PDMS mass spectrum and poster design is original
Students will make a puttylike material and test it for maximum bounce. Students will then use mass spectrometry as an analytical technique to determine if they can market their putty or if it is just a copy of Silly Putty ®.
What should students know as a result of this lesson?
- Students should know that polymers are repeating units of monomers and are useful to everyday life.
- Students should know that mass spectrometry is an analytical technique that can determine the types of elements and bonds that are in a compound.
What should the students be able to do as a result of this lesson?
- Students should be able to design a simple experiment to test for maximum bounce of their polymer.
- Students should be able to interpret a mass spectrum of a polymer and identify the molar mass of the repeating unit.
- For the making of the putty: White school glue (Elmer’s works well), Borax (laundry section of supermarket), water, 2 glass bottles for the reacting mixtures, plastic cups, plastic spoons for mixing, measuring cups, paper towels, plastic sealable bags.
- For the analysis of the PDMS (polydimethylsiloxane): Access to a mass spectrometer (Knight Chemical Laboratory- University of Akron) OR copies of the attached mass spectrum of PDMS.
- Students will be presented power point notes and online video clips explaining the concept of mass spectrometry.
- Students will go on a field trip to the Knight Chemical Laboratory/University of Akron Mass Spectrometry lab. (mass spectrums of PDMS are attached if this is impractical)
Assessment: formative assessments will be made during the notes and field trip during Q and A sessions.
- Students will work in pairs in the lab to create a puttylike material that has properties similar to Silly Putty ®. Students will adjust the ratios of the reacting materials to determine the one that produces maximum bounce of the polymer.
- Students will be able to observe the analysis of a polymer using the mass spectrometer.
Assessment: formative assessments will be made in the lab while the students are experimenting with their ratios of reactants to achieve maximum bounce.
- The concept of polymers being composed of repeating monomer units will be reinforced.
- Analysis of a mass spectrum will be explained and students will be taught how to determine the molar mass of the repeating monomer unit.
Assessment formative assessments will be taken as the lab groups analyze the mass spectrum of the PDMS.
Throughout the class, mass spectrometry will be referred to as an analytical technique that can determine what elements and bonds are in a certain compound. Mass spectrometry as a technique to determine average atomic mass will also be explained and assessed on a traditional end of course exam.
- Basic carbon chemistry- naming alkanes, alkenes, alkynes
- The mole concept and the calculation of molar mass
Best Teaching Practices
- Authentic Issue Based Learning
- Hands on/Minds on Learning
- Conceptual Understanding of Problem Solving
Alignment with Standards
*Essential knowledge 1.D.2: (from AP Chemistry course description at collegeboard.org)
b. Data from mass spectrometry also demonstrate direct evidence of different
isotopes from the same element.
- HS-ETS1-3 Engineering Design - Evaluate a solution to a complex real-world problem based on prioritized criteria and trade-offs that account for a range of constraints, including cost, safety, reliability, and aesthetics as well as possible social, cultural, and environmental impacts.
*From Ohio’s New Learning Standards: Science-Chemistry pg 298-299
- Molecules, ionic lattices and network covalent structures have different, yet predictable, properties
that depend on the identity of the elements and the types of bonds formed.
Students will need to have knowledge of basic carbon chemistry and its ability to form long repeating chains. Students will also need access to the internet to perform their research into Silly Putty’s® creation and chemical makeup.
- Goggles should be worn at all times during the making of the putty and in the mass spectrometry lab when analyzing the PDMS.
Students will know that mass spectrometry is an analytical technique that can identify the types of elements and bonds in a sample. This knowledge can be applied commercially to prevent trademark infringement.
- Students will communicate their findings in their lab notebooks when explaining how they determined their best ratio to achieve maximum bounce of the polymer. They will also include research into Silly Putty history and composition in their lab notebooks.
- Students will be assessed on their poster designs to market their homemade putty.
- Students should work in groups of 2 in the lab.
- Day 1: Students experiment in the lab to create their putty polymer and adjust ratios to achieve maximum bounce
- Day2: Lecture on organic monomers and polymers. Students explore history and general polymer makeup of Silly Putty ® using online resources.
- Day3: Students will take a field trip to the University of Akron- Knight Chemical Laboratory to visit the mass spectrometry lab and analyze a PDMS (the polymer that makes Silly Putty ®) mass spectrum. Students will also receive the rubric for their advertising posters.
- Day 3: Teacher will distribute copies of the attached mass spectrum of PDMS (polydimethylsiloxane) and help students to determine the molar mass of the repeating monomer unit. Students will receive rubric for their advertising posters.
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