Article Cite This: J. Chem. Educ. XXXX, XXX, XXX−XXX
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Adapting Meaningful Learning Strategies for an Introductory Laboratory Course: Using Thin-Layer Chromatography to Monitor Reaction Progress Nancy Wu, Ariana O. Hall, Sameer Phadke, Danielle M. Zurcher, Rachel L. Wallace, Carol Ann Castañeda, and Anne J. McNeil*
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Department of Chemistry and Macromolecular Science and Engineering Program, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109-1055, United States S Supporting Information *
ABSTRACT: Introductory-level laboratory courses provide students with hands-on experience using the discipline’s tools and theories. These courses often rely on recipebased experiments due to the constraints of large enrollments, short lab periods, and the desire to minimize complexity. In addition, covering a breadth of topics can lead to a fragmented curriculum with little carryover in learning from week to week. Herein, we describe an overhaul of an introductory organic chemistry laboratory curriculum, informed by the strategies of meaningful learning and a desire to make the course experience mimic a research lab. This new course, primarily taught to first-year undergraduate students at the University of Michigan, is framed with three interconnected modules. We present herein the first module, which focuses on thinlayer chromatography (TLC). In the first week, students learn how to perform TLC using a variety of compounds and solvent mixtures, gaining an understanding of how intermolecular interactions affect their retention. In the second week, they practice using TLC to distinguish reagents and reaction byproducts and in the third week apply TLC to monitor reaction progress and test their hypothesis. We assessed student learning through a writing assignment at the end of the three-week module. We also assessed how the overall course affects student comprehension of TLC concepts and confidence. Our findings suggest that this learn, practice, apply approach toward teaching introductory organic chemistry laboratory concepts leads to learning gains and increased confidence. KEYWORDS: Organic Chemistry, Hands-On Learning/Manipulatives, Inquiry-Based/Discovery Learning, Thin-Layer Chromatography
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spent in the laboratory should be both effective and efficient.4 Meanwhile, students are prioritizing completing their work on time and receiving credit for the course.8 Lab courses are both labor- and cost-intensive, leading Bretz to call on all chemists to collect evidence of student learning in their lab courses.9 Efforts to improve student learning experiences in introductory organic chemistry laboratories have been reported. Prelab assignments such as online videos and quizzes have been used to better prepare students for lab, enhance conceptual understanding10 and decrease anxiety.11 Some have used student-generated videos for instructional support.12,13 There is also a movement toward more problem-based and inquiry-based laboratory courses.14,15 Mohrig reported using an inquiry-driven organic chemistry laboratory that encouraged students to take more ownership of their lab work and become more independent and engaged in their learning.16 Experiments were spread over 2−4 laboratory periods to give
INTRODUCTION Laboratory courses provide opportunities for students to engage with the tools and theories of science through experimentation.1,2 In principle, these courses should epitomize active learning3 because students participate in hands-on experiments, draw on knowledge from current and previous courses, and apply that knowledge in different contexts. Instead, learning in lab courses can be fragmented because of a disconnect between concepts learned in one experiment to the next, missing a key opportunity to build off their learning from previous weeks.4 In addition, many lab courses still rely on recipe-like or expository experiments where the results are both known and unsurprising.5 One challenge associated with introductory laboratory courses is the wide range of learning goals that faculty aim to achieve,6 which are often misaligned with how students learn.7 In addition, the lab period itself can be hectic with students managing multiple tasks and goals: Students are learning new techniques while simultaneously trying to connect abstract concepts to the hands-on experiments. Students are also learning to adhere to safe practices and proper chemical handling. As a consequence, the time © XXXX American Chemical Society and Division of Chemical Education, Inc.
Received: March 26, 2019 Revised: May 24, 2019
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DOI: 10.1021/acs.jchemed.9b00256 J. Chem. Educ. XXXX, XXX, XXX−XXX
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We focused the first module on thin-layer chromatography (TLC) because of its widespread use in authentic research environments (e.g., synthetic laboratories in academia and industry) and its simplicity (e.g., low material costs and minimal technical skills required). Moreover, TLC reinforces the concepts of intermolecular interactions, a challenging topic for many introductory students.32 Similar principles guide separations in the commonly used high-pressure liquid chromatography and gas chromatography. The learning goals of this module were for students to know how to perform the technique (procedural), how and why the technique separates molecules (conceptual), and the purposes and applications of the technique. In the first week, students gain hands-on experience performing TLC on several different compounds under a variety of developing solvent conditions. The students interpret their results as well as their classmates’ results. In the second week, students practice their TLC skills by collectively identifying conditions that distinguish reagents and byproducts for an upcoming reaction. In the final week, students apply their TLC skills to test a hypothesis regarding the effect of reagent concentration on reaction rate. Using TLC to monitor reaction progress is the most authentic application of TLC in real-world research laboratories. At the conclusion of the module, the students individually submit a writing sample in response to a fictional blog post from a student who needs help with their TLC experiment. The students must identify the procedural and conceptual errors, offer practical suggestions for remedying these errors, and provide a scientific-based rationale for their advice. We present herein data demonstrating student comprehension of TLC concepts and procedures at the end of the three-week module and the term, as well as improvements in student confidence in carrying out experiments in the laboratory.
students more time to think and work on their laboratories. Students could repeat procedures to gain a better understanding and correct earlier mistakes. Collison et al. created a new curriculum based on “reformed experimental activities” that prompt students to derive hypotheses, test their skills without fear of failure, engage in peer discussion, and execute guided experiments.17 Students revisit the same substrates and techniques throughout the course, and with prodding, make connections between the lab with course content. Seery described a scaffolded design for an upper-level physical chemistry lab where students were tasked to design an experiment that meets a defined goal and builds off their first, recipe-based experiment.18 This approach minimizes cognitive load while simultaneously giving students a more authentic, research-like experience. Students can also benefit from laboratories that are threaded together with a common theme.19 For example, a year-long research-based organic chemistry course led students to think more about scientific discovery and less about the “right” outcomes of their work.20 One study limited the number of organic chemistry techniques and repeated them throughout the introductory lab course to enhance retention of course concepts.21 Integrating organic chemistry lab courses with other courses can help students understand applications and introduces students to crossdisciplinary collaborations.22−25 One way to increase student comprehension and engagement in an introductory laboratory course is to encourage meaningful learning,26 which occurs when a student purposefully connects new knowledge with their prior knowledge.27 For meaningful learning to take place, (1) students must have relevant prior knowledge to connect and position the new information, (2) the new information must be relatable to their existing knowledge, and (3) students must choose to relate the new information to their prior knowledge. In reality, a student’s approach to learning can sit somewhere on a continuum between rote and meaningful learning.28,29 Instructors can play a key role in selecting and presenting the course material to encourage students to employ meaningful learning strategies.27 Deeper comprehension often emerges from strategies that prompt learners to connect new information with prior knowledge, which is the foundation for constructing new knowledge.4,28,30 One way to encourage meaningful learning in a laboratory course is to continually build off concepts and techniques that were presented earlier in the same course. At the University of Michigan (U-M), the first (of two) introductory organic chemistry laboratory is taught to approximately 1700 students per academic year. Therefore, we have an extraordinary opportunity to transform how these students experience organic chemistry. For many students (48%), this course is their first college-level lab, which makes it an exceptional challenge to both equip students with fundamental lab skills and stimulate their learning with research-like activities. Herein we describe how we redesigned this introductory course, informed by the theory of meaningful learning.28 Each module starts with simple concepts and builds toward more complex concepts, consistent with best practices in complex learning environments.31 One strength of this course is the depth of student learning that can be achieved with experiments that are intentionally built off one another. This course also aims to mimic a research setting by having students formulate and test hypotheses by designing their own experiments.
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SETTING AND PARTICIPANTS This study was conducted at the University of Michigan, Ann Arbor, a public research university in the midwestern United States. Participants were students enrolled in the first (of two) introductory organic chemistry laboratory course in Fall 2017 and Winter 2018 (1 credit course). This class met weekly for a prelab lecture (50 min) taught by the course instructor and a laboratory section (3 h) taught predominantly by graduate student instructors. Neither the course instructor nor the graduate student instructors were involved in the data collection or analysis. Only the results of students who consented to research were analyzed, and institutional review board approval was obtained for all aspects of the study. The new curriculum was first piloted in Fall 2015 in a small section and subsequently underwent several substantive redesigns based on instructor feedback and observations. The curriculum was implemented in its fully optimized form on large scale for the first time in Fall 2017. As a consequence, our data analysis is from two terms: Fall 2017 and Winter 2018.
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NEW CURRICULUM
Course Overview
The redesigned course contains three modules, each focused on a different theme: thin-layer chromatography (TLC), liquid−liquid extraction (LLE), and green chemistry (GC). The course structure required students to transfer their knowledge from one module to another. For example, the TLC skills that students develop in the first module are used in B
DOI: 10.1021/acs.jchemed.9b00256 J. Chem. Educ. XXXX, XXX, XXX−XXX
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first week’s experiment was designed for students to learn how to perform TLC, troubleshoot their experimental techniques, and analyze unexpected results, mimicking aspects of an authentic research lab.34 This week’s experiment also encourages both cooperative and collaborative work among the students within and between their groups.
the second and third modules to determine whether their LLEs and reactions are successful. Each module involves three lab periods (3 h) that take place over 3 weeks. The lab periods are paired with a weekly prelab lecture taught by the course instructor, aimed at introducing the conceptual basis for the experimental work (see Supporting Information, SI). In addition, graduate student instructors provide just-in-time information during short presentations that occur at the start of each lab (SI). Throughout the course, students work both in pairs and in small groups (3−4 students) in sections with 18− 20 students. Students were graded on their participation and assignments, and they were not penalized for procedural mistakes. We describe herein the first module of the course, which is focused on TLC (Table 1).
Week 2: Practice
Week 2 builds on and extends the skills learned in the first week by having the students practice TLC by comparing the Rf’s for reagents and a byproduct of a future reaction under different solvent conditions. The goal is to prepare students to use TLC to monitor the progress of an organic reaction over time. In the prelab lecture for week 2, students are introduced to the mechanism of alkene bromohydroxylation (eq 1). This reaction is also taught (albeit a few weeks later) in the organic chemistry lecture course in which most students are coenrolled. The reaction goes to completion within 30 min, which is appropriate for the 3 h lab period.
Table 1. Course and TLC Module Overview General Module Structure
TLC Module
Week 1 Learn TLC basics Learn a new lab technique or concept Week 2 Determine best developing solvent system for a reaction Practice new technique or concept in a different context Week 3 Perform a reaction to test hypothesis and analyze results using TLC data Apply new technique or concept to answer a research question
In week 2, the students collaboratively determine the best TLC conditions for resolving the starting materials ((E)-1,2diphenylethene and N-bromosuccinimide (NBS)) and a stoichiometric byproduct (succinimide). Because you rarely have access to product when performing a new reaction in an authentic research lab, we chose to not provide students with a product standard for TLC. Working in small groups, each is assigned two different and unique TLC solvent conditions to evaluate. Students collect their data and share their Rf values in an online class spreadsheet for class discussion. Collectively, the class determines the optimal TLC conditions, which are then used in week 3. This exercise reinforces the relationship between compound structure and Rf that was first learned in week 1. The three compounds each have different intermolecular interactions (hydrogen bonding, dipole−dipole interactions, and dispersion forces) with the silica and solvent. By pooling the class data, students should see broader trends in how compounds move on the TLC plate than they would with only their group’s data. For example, three students (of five that we analyzed, see SI) concluded that their classmates’ solvent conditions led to better resolution on the TLC plate than their own solvent conditions. In addition, this week prepares the students to better understand whether their reaction in week 3 is progressing and when to stop it. Near the end of this lab period, the students are given a research goal for week 3: to probe the effect of NBS concentration on the rate of product formation. Students make a hypothesis (e.g., doubling the NBS concentration will double the rate) and provide their rationale based on scientific principles (e.g., the reaction is bimolecular in the ratedetermining step). Then they plan two experiments with differing NBS concentrations by modifying a generic procedure provided in the lab manual. Overall, this week’s experiment enables students to practice their TLC skills, as well as providing them with the experience of working out TLC conditions before starting their reaction, and guides them in formulating and testing their first hypothesis.
Week 1: Learn
The goals for week 1 are for students to gain experience with TLC by preparing samples, running them under different solvent conditions, and analyzing data. Each student is first assigned 1 of 10 compounds (SI). The students begin by considering the structural features of their compound and identifying the most relevant intermolecular interactions that are expected to take place between their compound and the silica and developing solvent. Students then work in pairs to learn the TLC technique and explore different troubleshooting tips, common mistakes, and reasons for expected or unexpected results. Students begin by preparing three dilutions of their assigned compound and spotting them on a TLC plate to identify the concentration that gives the best results. In addition, students determine which visualization method(s) work for their compound (UV light or an iodine stain) without developing the TLC plate. Students then work in pairs to spot and develop a single TLC plate in ethyl acetate/hexanes (50:50) with both compounds spotted adjacent to each other. They visualize spots and calculate each compound’s retention factor (Rf) under these conditions. Next, working again in pairs, students choose a different developing solvent ratio and observe how changes in solvent polarity affect the Rf using their previously determined dilution and visualization methods. Now, in groups of four, students compare their findings and discuss the effects of the compound structure and developing solvent composition on the Rf. Students rank the four compounds from low to high Rf values in a single solvent mixture and rationalize the ranking on the basis of the intermolecular interactions between their assigned compounds and the silica and solvent, a strategy adapted from the literature.33 Students enter the data for their compound, including the optimized dilution, solvent mixture, and Rf values, into a shared online spreadsheet for further discussion, led by the graduate student instructor. Overall, the C
DOI: 10.1021/acs.jchemed.9b00256 J. Chem. Educ. XXXX, XXX, XXX−XXX
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Figure 1. Details of the blog post assignment given to students.
Week 3: Apply
new reaction and the outcomes of their LLE purification. As a result, students build experience with the practice of TLC, while likely also enhancing their learning.
In week 3, students apply their newly gained TLC skills to collect data that will either support or refute their hypothesis. The students run their planned organic reactions using two different concentrations of NBS and use their optimized TLC conditions to monitor reaction progress. The TLC data should qualitatively show changes in the starting material and product concentrations over time (0, 1, and 30 min) based on their spot intensities. On the basis of their understanding of how the structure of a compound influences its movement on a TLC plate, students form a hypothesis about which new spot corresponds to the intended product, 2-bromo-1,2-diphenylethan-1-ol. Students then share and compare their data with the class and discuss any unexpected results. Because students observe multiple spots (including unidentified ones) on their TLC plates at the end of the reaction, instructors have an opportunity to introduce how chemists isolate pure products, alluding to the next module on LLE. This connection helps students understand the authentic contexts in which these techniques are used in research laboratories.
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RESULTS AND DISCUSSION Because TLC is the focus of the first module and is used continually throughout the semester, we assessed student comprehension at the end of the module and the course. We first assessed their learning at the end of the module through a writing assignment. Students were asked to analyze TLC data from a fictional student and offer practical suggestions for a future experiment (Figure 1). Students were expected to demonstrate an understanding of how TLC works, how intermolecular interactions influence Rf values, as well as how to troubleshoot a TLC experiment. Students were asked to provide a scientific principle-based rationale for their responses with as much detail as appropriate to teach another first-year organic chemistry student. Students individually completed this assignment outside the lab period and received written feedback and grades from the graduate student instructors who followed the same grading rubric (SI). All students were given the opportunity to revise and resubmit their assignment for a regrade. Representative work from a random selection of 50 students (25 from each term) was examined prior to their revision to identify common misconceptions. Common errors included confusing the terminology and/or concept of “polarity” (five students), confusing “intermolecular interactions” with “bond-
TLC Throughout the Course
For meaningful learning to occur in the laboratory setting, new knowledge should be built from prior knowledge. Therefore, students continue using TLC throughout the semester, each time in a new context. For example, in both the second and third modules, students use TLC to monitor the progress of a D
DOI: 10.1021/acs.jchemed.9b00256 J. Chem. Educ. XXXX, XXX, XXX−XXX
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Figure 2. Analysis of lab skills survey data for TLC-related questions from 1581 students.
compounds it is important to label each lane, but it is equally important to record which compound corresponds to each lane. Student 5: I would also recommend a better spotting technique for your spot in lane b so it will be more neat and clean. Perhaps making sure you do not spot too much compound on your baseline with your spotter. Student 6: There are several errors in the data analysis that you did. The Rf values calculated are all above 1 and therefore incorrect. The equation to determine Rf is Rf = distance traveled by compound/distance traveled by the solvent. The compound does not travel f urther than the solvent, therefore this value cannot be greater than 1. The Rf value should increase as the distance the compound travels increases; the spot closer to the solvent f ront, which is biphenyl, will have a higher value than the spot closer to the baseline, which is 4-phenylphenol. The second method of assessment was through ungraded Qualtrics surveys given at the start and conclusion of the course. We collected data and report results from the Fall 2017 and Winter 2018 semesters. Students received points for completing the “Lab Skills Survey” and bonus points for completing the “Attitudes Survey” (SI). In total, 1581 students participated in the lab skills survey and 1327 students participated in the attitudes survey. In the lab skills survey, students answered the same six multiple-choice questions at the beginning and end of the term to evaluate their understanding of TLC practice and concepts. Students were given a table with various solvents, their chemical structure, approximate pKa values, and densities (SI). The surveys were given during the lab period and the students were not allowed to consult any notes, peers, or outside resources. Herein, we present the data pertaining to TLC on the lab skills survey and the data on self-efficacy in the attitudes survey. To determine how the entire curriculum impacted student learning, we analyzed the ungraded lab skills survey questions given at the start and end of the term (SI). The presurvey was given during their first week of lab (during check-in and boot camp), prior to any instruction on TLC concepts or practice. The postsurvey was administered in their last week of lab, which is after they completed all three lab modules. We observed substantial gains in student understanding across the range of TLC questions (Figure 2). The largest gain (46% gain) between the pre- and postsurveys were questions about calculating Rf (Question 4) and determining the relative polarity of compounds based on the results of a TLC plate (Question 1) (see SI). Significant gains were also seen in their understanding of what the mobile phase is (33% gain) and how to troubleshoot a “smudged” spot on the plate (27%
ing” (three students), mislabeling or misidentifying the type of intermolecular interactions (four students), and a misunderstanding of how TLC works (e.g., the nonpolar compound has the lower Rf) (four students). In addition, representative work from 10 additional students was analyzed in more detail (8 of these were revisions). Five students were randomly selected from the pool of students who scored below 90% on the assignment and five students were randomly selected from students who scored 90% or above. The following quotes come from students in both populations. In the assignment, students demonstrated both a procedural and conceptual understanding of TLC as a separation technique. Student 1. The TLC plate is made of silica, which signifies that there will be a lot of hydrogen bonding sites. If the compound that was spotted on the silica plate has a stronger interaction with the plate than the solvent, it will stay near the baseline, which means that in the competition between the plate and the solvent silica on the plate has a greater pull on the compound than the solvent does. Students also demonstrated that they can logically interpret TLC data: Student 2: Taking a look at the two compounds used in this experiment, biphenyl and 4-phenylphenol are both very similar structures. However, 4-phenylphenol has a hydroxyl group which makes it more likely to partake in stronger interactions with the silica (such as hydrogen bonding or dipole−dipole interactions) which should make its spot appear closer to the baseline. Student 3: Remember that more polar compounds will have a lower Rf because they’ll be more strongly attracted to the silica plate, which includes alcohol groups capable of hydrogen bonding. Biphenyl consists of two unsaturated hydrocarbon rings, so everything is fairly nonpolar. Granted there are small dipoles involved in each carbon−hydrogen bond, but those mostly cancel out based on their positions, so van der Waals interactions are the strongest attractive force between the silica plate and biphenyl. These are insignificant when compared to the hydrogen-bonding potential that 4-phenylphenol has because of its alcohol group. Based on that rationale the 4-phenylphenol should have traveled the shortest distance from the baseline and corresponds to the spot lower on your plate, and the biphenyl should have traveled farther and corresponds to the highest spot on your plate. Furthermore, there is a clear demonstration that students have learned the practice of TLC and can communicate that knowledge to someone else: Student 4: It is incredibly important to label every compound that you use during an experiment. If you are spotting multiple E
DOI: 10.1021/acs.jchemed.9b00256 J. Chem. Educ. XXXX, XXX, XXX−XXX
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gain). Interestingly, smaller gains were observed in the questions that they focused on at the start of the term, including what happens to the Rf if you change the solvent polarity (14% gain) or increase the TLC plate size (5% gain). Overall, the majority of students learned these concepts by the end of the course with a range of 47−82% correct across all questions. A third method of assessment involved examining the students’ data and interpretation skills in their lab notebooks. Even though the experiments were performed in groups, each student was individually responsible for submitting their own notebook online at the end of the module. A random selection of five students were chosen for analysis (see SI). Students relied on two factors to determine which solvent conditions were optimal for reaction monitoring in week 3: (i) whether the conditions gave Rf values that fall within the range suggested in prelab lecture (0.2−0.8), and (ii) which conditions provided the best separation of the three components. Three students chose a solvent combination identified by their peers, reinforcing the collaborative approach to this experiment. All five students were able to identify that the more polar product should have a lower Rf value than the less polar alkene starting material, but there was less consensus on whether the product should have a higher or lower Rf value than NBS and succinimide. When considering these relative Rf values, three students rationalized their hypothesis based on anticipated hydrogen-bonding interactions between these compounds and the silica plate. These combined results suggest that the students have learned how intermolecular interactions impact TLC results. During the reaction, four students saw larger/darker intensities for the product spot in the reaction with excess NBS, while one student saw no difference. Three of the four students concluded that this data supported their hypothesis that an increased NBS concentration would increase the reaction rate. A representative quote is as follows: The TLC plate that had 0.8 mmol NBS had a larger and darker spot at 1 min than the TLC plate that had 0.2 mmol meaning more products were produced with the higher concentration of NBS. One student was confused on which reagent was limiting, which clouded their ability to draw a conclusion from this experiment. Overall, we found that the students were able to identify optimized solvent conditions based on section-wide shared data, make a hypothesis about which new spot corresponded to the product by considering intermolecular interactions, and draw conclusions based on their TLC data while monitoring of reaction progress. We also asked students to rank their confidence levels in performing various tasks in a chemistry laboratory at the start and end of the term in an online survey adapted from Bowen.35 Our results showed gains in student confidence after completing the entire course (Figure 3). For example, only 23% of students indicated a 5 (very confident) for their confidence in carrying out procedures in a chemistry laboratory at the start of the term while 42% were “very confident” at the end of the term. Overall, 86% of students indicated a 4 or 5 for this measure at the end. Surprisingly, we did not see a large change in student confidence regarding their ability to interpret data in the chemistry laboratory. Within the entire student population studied, 66% of the students ranked their confidence with a 4 or 5 at the beginning of the course, and this number did not change significantly by the end of the
Figure 3. Analysis of attitudes survey for questions relating to confidence in the lab for 1581 students.
course (69%). However, analysis of their writing samples suggested that they have learned how to logically interpret TLC data. In light of this contradiction, we suggest more intentional framing during the course of what it means to interpret data, including highlighting how their blog post assignment is an example of data interpretation. Overall, our students showed that they have a grasp of the conceptual and procedural details of TLC, including how to use it in the laboratory and how to interpret the results. As a result of the entire course, students report increases in confidence in their ability to collect data, use equipment, and carry out procedures in the chemistry lab. Limitations
Our meaningful learning approach requires continually building off skills gained earlier in the course, and as a consequence, fewer techniques can be introduced within the semester. Consistent with the less-is-more philosophy, Young et al. have shown that students who performed half as many experiments as the traditional course performed similar to, and in some cases better than, students enrolled in the traditional lab course.36 Another limitation is that the meaningful learning approach can be diminished when the instructors provide answers to maximize time efficiency and minimize student struggles. To attenuate this concern, we provide training on the meaningful learning approach to the graduate student instructors at the start of the term. In addition, we provide the instructors with a weekly 1-page summary sheet (SI) highlighting the key concepts and how to avoid common experimental pitfalls, as well as a short presentation (SI) to deliver at the start of each lab period, which presents just-intime information, including proper experimental techniques, safety concerns, and leading questions for whole class discussion. Our goal is to provide multiple forms of support to instructors to help students make connections in a more meaningful way.
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CONCLUSIONS We demonstrated herein that meaningful learning strategies can be adapted for use in an introductory laboratory setting. We described the first module that focuses on TLC and showed how students gained experience in performing TLC, understanding how the intermolecular forces between compounds affect the results, and applying TLC to monitor reaction progress. We assessed student learning at the end of the module as well as at the end of the course and found gains F
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Student Learning in Chemistry; ACS Symposium Series; American Chemical Society: Washington, DC, 2016; Chap 6. (8) DeKorver, B. K.; Towns, M. H. General Chemistry Students’ Goals for Chemistry Laboratory Coursework. J. Chem. Educ. 2015, 92, 2031−2037. (9) Bretz, S. L. Evidence for the Importance of Laboratory Courses. J. Chem. Educ. 2019, 96, 193−195. (10) Nadelson, L. S.; Scaggs, J.; Sheffield, C.; McDougal, O. W. Integration of Video-based Demonstrations to Prepare Students for the Organic Chemistry Laboratory. J. Sci. Educ. Technol. 2015, 24, 476−483. (11) Chaytor, J. L.; Al Mughalag, M.; Butler, H. Development and Use of Online Prelaboratory Activities in Organic Chemistry to Improve Students’ Laboratory Experience. J. Chem. Educ. 2017, 94, 859−866. (12) Benedict, L.; Pence, H. E. Teaching Chemistry Using StudentCreated Videos and Photo Blogs Accessed with Smartphones and Two-Dimensional Barcodes. J. Chem. Educ. 2012, 89, 492−496. (13) Box, M. C.; Dunnagan, C. L.; Hirsh, L. A. S.; Cherry, C. R.; Christianson, K. A.; Gibson, R. J.; Wolfe, M. I.; Gallardo-Williams, M. T. Qualitative and Quantitative Evaluation of Three Types of Student-Generated Videos as Instructional Support in Organic Chemistry Laboratories. J. Chem. Educ. 2017, 94, 164−170. (14) Gaddis, B. A.; Schoffstall, A. M. Incorporating Guided-Inquiry Learning into the Organic Chemistry Laboratory. J. Chem. Educ. 2007, 84 (5), 848−851. (15) Mistry, N.; Fitzpatrick, C.; Gorman, S. Design Your Own Workup: A Guided-Inquiry Experiment for Introductory Organic Laboratory Courses. J. Chem. Educ. 2016, 93, 1091−1095. (16) Mohrig, J. D.; Hammond, C. N.; Colby, D. A. On the Successful use of Inquiry-Driven Experiments in the Organic Chemistry Laboratory. J. Chem. Educ. 2007, 84, 992−998. (17) Collison, C. G.; Kim, T.; Cody, J.; Anderson, J.; Edelbach, B.; Marmor, W.; Kipsang, R.; Ayotte, C.; Saviola, D.; Niziol, J. Transforming the Organic Chemistry Lab Experience: Design, Implementation, and Evaluation of Reformed Experimental Activities − REActivities. J. Chem. Educ. 2018, 95, 55−61. (18) Seery, M. K.; Jones, A. B.; Kew, W.; Mein, T. Unfinished Recipes: Structuring Upper-Division Laboratory Work to Scaffold Experimental Design Skills. J. Chem. Educ. 2019, 96, 53−59. (19) Bieron, J. F.; McCarthy, P. J.; Kermis, T. W. A New Approach to the General Chemistry Laboratory. J. Chem. Educ. 1996, 73 (11), 1021−1022. (20) Newton, T. A.; Tracy, H. J.; Prudenté, C. A Research-Based Laboratory Course in Organic Chemistry. J. Chem. Educ. 2006, 83, 1844−1849. (21) Russell, C. B.; Mason, J. D.; Bean, T. G.; Murphee, S. S. A Student-Centered First-Semester Introductory Organic Laboratory Curriculum Facilitated by Microwave-Assisted Synthesis (MAOS). J. Chem. Educ. 2014, 91, 511−517. (22) Boltax, A. L.; Armanious, S.; Kosinski-Collins, M. S.; Pontrello, J. K. Connecting Biology and Organic Chemistry Introductory Laboratory Courses through a Collaborative Research Project. Biochem. Mol. Biol. Educ. 2015, 43, 233−244. (23) Esselman, B. J.; Hill, N. J. Integration of Computational Chemistry into the Undergraduate Organic Chemistry Laboratory Curriculum. J. Chem. Educ. 2016, 93, 932−936. (24) Kjonaas, R. A.; Fitch, R. W.; Noll, R. J. Cross-Course Collaboration in the Undergraduate Chemistry Curriculum: Isotopic Labelling with Sodium Borodeuteride in the Introductory Organic Chemistry Laboratory. J. Chem. Educ. 2017, 94, 1334−1337. (25) Van Hecke, G. R.; Karukstis, K. K.; Haskell, R. C.; McFadden, C. S.; Wettack, F. S. An Integration of Chemistry, Biology, and Physics: The Interdisciplinary Laboratory. J. Chem. Educ. 2002, 79 (7), 837−844. (26) Ausubel, D. Educational Psychology: A Cognitive View; Holt, Rinehart, and Winston, Inc.: New York, 1968; pp 37−39.
in both student comprehension and confidence. The TLC module also mimicked a research setting, enabling students working in groups to formulate and test hypotheses using organic chemistry techniques. Importantly, all of this work was done at a large scale, with 700−1100 students enrolled per term. As such, the methods and approaches we present in this paper could be useful for other large institutions that want to emphasize a research-like component in their large enrollment, introductory laboratory courses.
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ASSOCIATED CONTENT
S Supporting Information *
The Supporting Information is available on the ACS Publications website at DOI: 10.1021/acs.jchemed.9b00256.
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Learning objectives, course outline, prelab lectures, graduate student instructor presentations and handouts, laboratory manual, and survey results (PDF)
AUTHOR INFORMATION
Corresponding Author
*E-mail:
[email protected]. ORCID
Nancy Wu: 0000-0001-8901-6030 Rachel L. Wallace: 0000-0002-0637-3970 Carol Ann Castañeda: 0000-0002-1233-4062 Anne J. McNeil: 0000-0003-4591-3308 Notes
The authors declare no competing financial interest.
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ACKNOWLEDGMENTS This work was supported by the Howard Hughes Medical Institute (HHMI) through a Professors Program grant to A.J.M. (#52008144). We gratefully acknowledge the many people who have contributed to the new curriculum over the years via thoughtful and engaging discussions, including my faculty colleagues, the enrolled students, and their graduate student instructors, as well as other graduate and undergraduate student assistants.
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REFERENCES
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