Chemistry

Using Life Cycle Data to Help Teachers Understand Key Energy Concepts

Day: 
Tues

Participants engage in and provide feedback on digital interactive learning experiences that use National Renewable Energy Laboratory life cycle data and help teachers understand key energy concepts. Please bring your laptop.

Date/Time: 
9:45 am to 11:45 am
2014 Session Types: 
Feedback Session (Work in Development)
Session Materials: 

Biological Sciences Curriculum Study (BSCS) and project partners are developing an online course for high school science teachers. The purpose of the course is to help teachers understand key energy concepts in alternative energy contexts. The course includes three interactive learning experiences (interactives) that use life cycle data from the National Renewable Energy Lab (NREL).

Preparation and Characterization of a Polymeric Monolithic Column for Use in High-Performance Liquid Chromatography (HPLC)

Author/Presenter: 
Michael P. Bindis
Stacey Lowery Bretz
Neil D. Danielson
Lead Organization(s): 
Year: 
2011
Short Description: 
The high-performance liquid chromatography (HPLC) experiment, most often done in the undergraduate analytical instrumentation laboratory course, generally illustrates reversed-phase chromatography using a commercial C18 silica column. To avoid the expense of periodic column replacement and introduce a choice of columns with different stationary phases, we have developed an experiment in which students prepare and test a polymer-based monolithic column. The 10 or 15 cm monolithic column is prepared using 1/8 in. o.d. × 2.3 mm i.d. poly(ether ether ketone) or PEEK tubing. The reaction is accomplished thermally at 60 °C for several hours by polymerization of butyl methacrylate cross-linked with ethylene glycol dimethacrylate in a porogen system consisting of 1,4-butanediol, 1-propanol, and water. Using toluene and naphthalene as analytes, profiles of retention factor as a function of methanol have been shown. A study of essential nutrients can be accomplished by using an ion-pairing reagent to separate thiamine from riboflavin. In addition, plate count and van Deemter plots can be done to determine column efficiency. The experiment can be designed to be completed over a 1 to 3 week period of time. Exposure to polymer chemistry, often not a part of the undergraduate laboratory curriculum, is an additional important aspect of this experiment.

Synthesis and Characterization of Self-Assembled Liquid Crystals: p-Alkoxybenzoic Acids

Author/Presenter: 
Jana Jensen
Stephan C. Grundy
Stacey Lowery Bretz
C. Scott Hartley
Lead Organization(s): 
Year: 
2011
Short Description: 
Thermotropic liquid crystal phases are ordered fluids found, for some molecules, at intermediate temperatures between the crystal and liquid states. Although technologically important, these materials typically receive little attention in the undergraduate curriculum. Here, we describe a laboratory activity for introductory organic chemistry students on the synthesis and characterization of the p-alkoxybenzoic acids. These compounds, through the formation of carboxylic acid dimers, exhibit liquid crystal phases common in rod-like (calamitic) molecules. The students are assigned different alkoxy chain lengths and synthesize the compounds through microwave-assisted nucleophilic substitution. Characterization of the phase behavior is then carried out by standard melting point techniques, differential scanning calorimetry, or polarized optical microscopy. The results for the class are pooled to allow the students to consider structure–property effects for the series. This activity allows students to explore small-molecule synthesis applied to materials chemistry and concepts of self-assembly: the benzoic acids associate through hydrogen bonding, and the resulting rod-like dimers further organize into the liquid crystal phases.

A Symmetry POGIL Activity for Inorganic Chemistry

Author/Presenter: 
Cynthia J. Luxford
Michael W. Crowder
Stacey Lowery Bretz
Lead Organization(s): 
Year: 
2012
Short Description: 
The goal of this project was to create an inquiry activity to teach symmetry elements and symmetry operations in an inorganic chemistry course. Many students experience difficulty when building and mentally manipulating three-dimensional mental models from two-dimensional images, causing difficulty when learning symmetry. Process-oriented, guided-inquiry learning (POGIL) was used to structure the activity using a learning cycle paradigm consistent with research on how students learn as described by Novak’s human constructivism theory. The activity familiarized students with symmetry terms as students actively engaged in finding symmetry operations in a variety of molecules. The symmetry activity was classroom tested and student and POGIL expert feedback were used to improve the activity.

Development and Assessment of A Diagnostic Tool to Identify Organic Chemistry Students’ Alternative Conceptions Related to Acid Strength

Author/Presenter: 
LaKeisha M. McClary
Stacey Lowery Bretz
Lead Organization(s): 
Year: 
2012
Short Description: 
The central goal of this study was to create a new diagnostic tool to identify organic chemistry students’ alternative conceptions related to acid strength. Twenty years of research on secondary and college students’ conceptions about acids and bases has shown that these important concepts are difficult for students to apply to qualitative problem solving. Yet, few published studies document how students’ prior knowledge of acids influences their understanding of acid strength in organic chemistry contexts. We developed a nine-item multiple-tier, multiple-choice concept inventory to identify alternative conceptions that organic chemistry students hold about acid strength, to determine the prevalence of these conceptions, and to determine how strongly these conceptions bias student reasoning. We identified two significant alternative conceptions that organic chemistry students hold about acid strength. Students who answered items incorrectly were more confident about their answers than peers who answered items correctly, suggesting that after one semester of organic chemistry, students do not know what they do not know. Implications for the teaching of acid strength are discussed.

Target Inquiry: Transforming In‐Service Teacher Professional Development and Instruction in High School Chemistry (Yezierski, Herrington)

Author/Presenter: 
Ellen Yezierski
Deborah Herrington
Year: 
2009
Short Description: 
This session presents results of a four-year longitudinal, mixed-methods study showing how Target Inquiry affects teacher beliefs, transforms teacher practice, and increases student achievement.

Synthesis and Characterization of Self-Assembled Liquid Crystals: p-Alokxybenzoic Acids

Thermotropic liquid crystal phases are ordered fluids found, for some molecules, at intermediate temperatures between the crystal and liquid states. Although technologically important, these materials typically receive little attention in the undergraduate curriculum. Here, we describe a laboratory activity for introductory organic chemistry students on the synthesis and characterization of the p-alkoxybenzoic acids. These compounds, through the formation of carboxylic acid dimers, exhibit liquid crystal phases common in rod-like (calamitic) molecules.

Author/Presenter: 
Jensen, Jana
Grundy, Stephan
Bretz, Stacey Lowery
Hartley, C. Scott
Year: 
2011

Pages

Subscribe to Chemistry