Development and Implementation of Problem-based Chemistry Experiments for Engineering Students in a Multi-disciplinary Course

This paper will describe the implementation and continuing development of five problem based laboratory experiments in a general chemistry course designed specifically for multiple disciplines of engineering students at the University of New Haven. The Problem Based Laboratory Experiments (PBLE) were developed to provide students with the opportunity to perform and develop experimental procedures working in interdisciplinary teams, while achieving a greater understanding of the role of chemistry in engineering fields. In each PBLE, students first complete a traditional chemistry experiment to gain an understanding of the chemical concepts and to become familiar with executing a written procedure with a specific goal. Following this, students are presented with an engineering driven problem or task related to the chemical concepts. Students use knowledge obtained from the previously completed process to design an experiment addressing the problem. In place of formal laboratory reports, students create technical memos, written by rotating team leaders, that includes their recommendations or responses to the presented problem. All recommendations must be based on their devised experimental approach and the actual data that was obtained. Students are also required to complete an error analysis by considering changes to improve data acquisition, should the experiment be run again. The technical memos are graded against a defined rubric that assesses the work with a focus on the designed experimental approach, data reporting and presentation, and recommendations based heavily upon those results. The grading is designed to allow students a level of academic freedom from right and wrong answers, focusing instead on understanding the value of working with data obtained from an experimental process and making recommendation based upon those results. The development of skills needed to solve problems is important for both chemists and engineers. The problem based learning experience brought students beyond following simple protocols and procedures and gave students experience in an analytical design process, collaboration and technical writing. The goal of designing and implementing the PBLEs was to integrate a problem based learning experience while increasing levels of student engagement in comparison to more traditional chemistry experiments. Introduction Problem based learning is a learner-centered approach to instruction that encourages students to conduct research while integrating theory, knowledge and skills to develop a solution to a defined problem. Engineering instruction integrates well into problem based learning, allowing students real world problem solving experience in a classroom setting. It has been utilized in materials courses to examine material strengths and in mechanical engineering courses to examine system behavior and fluid dynamics. It has been utilized in chemistry instrumentation laboratories built around medical case analysis of drug analysis and quality controls in breweries. With its increasing use, students have benefit from the engaging scenarios, where learning gains have been found to be twice that of a traditional classroom setting. In addition to problem solving, collaboration is a key component as future engineers must be able to adopt strategies and tools for a multiple perspectives approach to better understand complex engineering problems. At the University of New Haven, engineering curriculum has been designed to support interdisciplinary learning with a multidisciplinary approach called The Spiral Curriculum. Unlike the traditional approach, the spiral curriculum introduces foundation courses with a mix of engineering topics including electrical circuits, fluid mechanics, heat transfer, material balances, properties of materials, structural mechanics and thermodynamics. The topics are presented in a variety of disciplinary contexts within the first two years of undergraduate education. A solid background is developed by touching key concepts at several points through the education process in different courses, adding depth and complexity at each pass. General Chemistry with Application to Biosystems is a course developed specifically for engineers in the Spiral Curriculum. Developed in 2004, the goal was to introduce multiple disciplines of engineering students to quantitative and qualitative aspects of general chemistry, while examining its role in various biological systems. Past feedback from the course indicated that engineering students often had trouble appreciating the value of chemistry or biology in their educational experience. Therefore, the lecture portion of the course was further linked to examine chemical and biological ideas within other engineering topics. Since the course’s development in 2004, many of the laboratory experiments stemmed from a traditional General Chemistry 2 Laboratory. While some biological components were integrated, the overall structure of the class was similar to that of a chemistry laboratory, where a series of one-day experiments with multiple trials were done. The goal was to integrate the problem based learning approach to create an experimental process that would better align with what engineers might experience in other project based courses using a series of problem based learning experiments (PBLE) while increasing student engagement in comparison to traditional chemistry experiments. Laboratory Development The experimental topics were determined using previous chemistry experiments presented in the course. A team of teaching assistants, along with the course coordinator, developed an engineering driven problem to build off existing labs. These replaced the traditional chemistry labs as found in Table 1. Table 1. Comparison table of changes for PBLE implementation Traditional Laboratory Experiments Problem Based Laboratory Experiments Week 1 Statistics and Experimentation Freezing Point Depression and Examination Quality of Various Deicers Week 2 Freezing Point Depression Week 3 Rates of Reaction Polymer Development and Examination of Polymer/Initiator Ratios with Strength Testing Week 4 Temperature and Catalyst Week 5 Equilibrium Constant Solubility of Ionic Compounds Procedure Examination of Removing Metal Contamination from Water Sample Week 6 Acid and Base Behavior Week 7 Acid-Base Behavior of Amino Acids Examination of Chemical Versus Biological Catalysts Using Reaction Rates Week 8 Buffers Week 9 Dissolved Oxygen Chemical Battery Procedure and Examination of Varying Metals in Batteries Week 10 Biochemical Oxygen Demand Prior to leaving the laboratory on Week 1, students are presented with the problem portion of the lab; a task or problem that they would need to solve in Week 2. Students would then be required to design an experimental procedure in order to help answer the problem. Most of the PBLEs were developed so students could create a variation of the Week 1 procedure to develop a testing process for the Week 2 problem (Table 2). The PBLEs were designed using a 2-week schedule for each experiment. Week 1 used an experimental process that would have been used in a traditional General Chemistry Laboratory, consisting of multiple trials using a step-by-step procedure. This gave students an understanding of what processes might be done in a lab with the given chemicals and glassware, as well as a specific set of knowledge and skills. Table 2. Problem Based Laboratory Overview By Experiment Experiment Problem Presented Week 1 Process Week 2 Process Chemical Concepts Examination Quality of Various Deicers Recommend the best de-icer that your company should use: properties, cost, environmental, etc. Determine the freezing point depression and constant of cyclohexane Develop a process to evaluate the effectiveness of various de-icers based on freezing point depressions colligative properties, intermolecular forces, experimental development Examination of Polymer/Initiator Ratios with Strength Testing Determine best monomer to catalyst ratio and synthesis conditions to create strongest polymer Synthesize polymer Polycaprolactone under various conditions: time, temp, monomer ratio Evaluate polymers created with qualitative and quantitative tests intermolecular forces, advanced materials, experimental development Examination of Removing Metal Contamination from Water Sample Remove heavy metal contamination from a water samples Examine various precipitation reactions with solutions and concentrations that effectively remove ions Develop a process using precipitation reactions to remove unwanted ions out of water, verifying results precipitation reactions, solutions, spectroscopy, experimental development Examination of Chemical Versus Biological Catalysts Using Reaction Rates Understand how concentration of a catalyst affects the rate law of the reaction, and which catalyst is best Determine rate law of the decomposition of a reaction involving hydrogen peroxide and potassium iodide Determine rate law of the decomposition of hydrogen peroxide and catalase rate of reactions, mechanisms, oxidation and reduction, catalyst, experimental development Examination of Varying Metals and Chemicals in Batteries Find the best combination of anode/cathode to give the highest voltage output Understand how a Galvanic Cell works, and explore various concentrations of solutions Explore different combinations of metals and solutions to make different Galvanic Cells electrochemistry, oxidation and reduction, experimental development The Use of Technical Memos In industry, engineers possess the technical knowledge and are often relied on by members of a team or company to solve a problem. For this reason, engineers need to be able to properly communicate their thoughts and observations about the issue at hand. Technical writing and presentations are how engineers report out findings. The technical memo format adopted by the courses within the spiral