Second-semester General Chemistry Research Articles

Importance of Academic Legacy on Student Success in First- and Second-Semester General Chemistry

This investigation sought to elucidate the influence of students' academic legacy on their prior knowledge and course outcomes providing crucial insights for educators who teach general chemistry. This six-semester analysis involved 6,914 students enrolled in classes across nine Texas universities. Explored were personal circumstances associated with students' successes and failures that influenced performance in on- and off-sequence, first- and second-semester general chemistry (Chem 1 and Chem 2). Students' academic legacy based on their categorization as first generation (neither grandparent nor parent/guardian with a 4-year bachelor's degree), second generation (at least one grandparent or parent/guardian with a bachelor's degree), or third generation (at least one grandparent and at least one parent/guardian hold a bachelor's degree) was investigated. Of the students in the dataset 33.8% (<i>n</i> = 2,340) self-identified as Hispanic. Results for Hispanic and non-Hispanic students indicated that first-generation students struggled more with Chem 1 and Chem 2 than students in the other two legacy groups. As students' academic legacy extended, they were more apt to succeed in general chemistry. Second- and third-generation students demonstrated stronger prior high-school chemistry backgrounds and were enrolled in more advanced mathematics courses. As expected, students with stronger academic backgrounds in chemistry and mathematics scored higher on the diagnostic MUST (Math-Up Skills Test), had greater self-efficacy relative to their preparation to succeed, and reported fewer paid work hours. First-generation students on the average entered with lower diagnostic MUST scores, felt less prepared to succeed, and disclosed a greater need to be employed.

Looking to Move Away from Expository General Chemistry Laboratories? We May Have a Cure for What “Ales” You

The two-semester General Chemistry laboratory sequence for nonchemistry majors at James Madison University has recently made the transition from expository, confirmation experiments to project-based (first semester) and research-based (second semester) curricula; this narrative will describe the development and current state of the Brewing Science (BrewSci) second-semester course. This high-enrollment service course with typically ∼25 sections (maximum enrollment of 24 students per section) offered during the regular two-semester school year was designed to leverage the skills obtained in a research-based environment: problem-solving, creativity, teamwork, communication, etc. The synthesis (brewing) and analysis of beer was selected as a vehicle for the learning goals due to the range of variables that can be manipulated, the wealth of relevant chemistry/biochemistry content suitable for a second-semester General Chemistry course, and the relative safety of the brewing process. Teaching supports, including trained undergraduate Learning Assistants, have been developed and employed to ensure the course can be taught by any of the rotating cohort of full-time or part-time faculty members. Analysis of course success rates (students earning a C– or higher) and DFW rates indicates improved student outcomes. Further, preliminary analysis of student survey data indicates improved student perceptions of their own abilities to think and act as scientists. Instructors corroborated these findings in a separate survey. Following the successful establishment of the BrewSci version of the General Chemistry 2 lab, the same curriculum development model is now being leveraged to expand offerings to other areas of faculty and student interest.

Evaluating Peer-Led Team Learning Integrated into Online Instruction in Promoting General Chemistry Student Success

This study seeks to examine the effectiveness of peer-led team learning (PLTL) pedagogy when it is implemented in an entirely online environment. Past evaluations of PLTL have demonstrated the effectiveness of this approach when used with in-person teaching, but an online environment is expected to pose unique challenges to students, and therefore, the past work may not generalize to an online environment. The study implemented PLTL within four classes of second-semester general chemistry each offered online. The classes were evaluated in reference to six classes of the same course, also taught exclusively online, that relied primarily on didactic instruction. The evaluation showed the average score for students with online PLTL ranged from 0.15 to 0.20 standard deviations better than students with online didactic across the tests and final exams and that this difference was partially explained by past performance. Further, online PLTL students had a higher likelihood of earning a passing grade in the class which corresponded with a lower proportion of students failing and a lower proportion of students withdrawing from the course. The results indicate that PLTL was an effective instructional technique within an online modality at the research setting.

Is the STEM Gender Gap Closing?

The Networking for Science Advancement (NSA) team's institutions consist of nine universities located in one large southwestern state. This study evaluated students enrolled from Spring 2017 to Fall 2019 in first- and second-semester general chemistry. Over 90% of the students (n = 6,694) have been exposed to a secondary school isomorphic curriculum. The population studied, Chem I (n = 4,619) and Chem II (n = 2,075), met entry-level criteria and are therefore expected to succeed (i.e., earn grades of A, B or C). This study's focus is to disaggregate data based on binary gender (M/F) in hopes of revealing patterns that might remain hidden when studying an undivided population. In Chem I, the female population was 59.6% and increased to 64.5% for Chem II. The 15-min., diagnostic Math-Up Skills Test’s (MUST) scores identified about half of all students who were unsuccessful (grades of D and F). Results from the study support that males enter Chem I and II with better automaticity skills (what can be done without using a calculator) than females. However, females outperformed males on course averages in Chem I but not Chem II. Our data provide supporting evidence that the gender gap may be closing.

Early Warning Signals from Automaticity Diagnostic Instruments for First- and Second-Semester General Chemistry

The Math-Up Skills Tests (MUST) has been used in multiple research projects conducted by the Networking for Science Advancement (NSA) team to determine how automaticity skills (what can be done without a calculator) in arithmetic can be used to predict if students will be successful (course average = 69.5%+) in general chemistry. This study expands our investigations to include how students’ quantitative literacy/quantitative reasoning (QL/QR) abilities influence their success. The NSA team studied multiple classes at eight universities (n = 1,915) within a broad geographic setting in one large, majority-minority southwestern US state. In a short amount of required classroom time, it is possible to identify students at the beginning of the semester who will struggle in first- and second-semester general chemistry (Chem I and Chem II). Results show a strong correlation between students’ automaticity MUST skills and their QL/QR ability (r = 0.60) and indicate that when taking both diagnostic assessments into consideration, convincing signals appear allowing for the identification of almost 50% of the Chem I students and about 45% of the Chem II students who will not succeed. With the addition of the QL/QR to the first-week assessments, about 9% more students who enter the courses underprepared were identified than when only the MUST was administered. Outcomes indicate that students with at least average arithmetic and QL/QR automaticity abilities are those who are better prepared for these courses. For on-sequence students with at least one average or above diagnostic score, 88.3% Chem I and 90.5% Chem II were successful.

Investigating the Impact of Assessment Practices on the Performance of Students Perceived to Be at Risk of Failure in Second-Semester General Chemistry

Investigating the Impact of Assessment Practices on the Performance of Students Perceived to Be at Risk of Failure in Second-Semester General Chemistry

Measuring Changes in Undergraduate Chemistry Students’ Reasoning with Reaction Coordinate Diagrams: A Longitudinal, Multi-institution Study

The Reaction Coordinate Diagram Inventory (RCDI) was developed to measure chemistry students’ thinking and confidence when interpreting the kinetic and thermodynamic information encoded within reaction coordinate diagrams (RCDs). The RCDI was designed based upon analyses of qualitative data collected in semi-structured interviews with general chemistry students or organic chemistry students to ensure all items and distractors were grounded in students’ ideas and reasoning. A longitudinal, multi-institution research study was conducted using the RCDI to measure changes in undergraduate chemistry students’ reasoning with RCDs, and their confidence in doing so, at three points in time: (1) end of second-semester general chemistry, (2) beginning of first-semester organic chemistry, and (3) end of first-semester organic chemistry. The three institutions participating in this longitudinal study taught organic chemistry using either a traditional functional group curriculum or a mechanisms approach. Findings include evidence that individual students performed significantly better with significantly higher confidence as they progressed through courses, but that some RCD misconceptions, such as incorrectly assuming reaction progress indicates a time unit, are persistent throughout. Although two of the institutions taught organic chemistry using a mechanisms curriculum and one institution used the traditional functional group approach, no evidence exists of significant differences among students’ RCDI total score and average confidence across institutions.

An Undergraduate Experiment to Investigate Air Pollutants Created from Lightning

Chemistry of the environment has been a long-standing and important area of scientific research. Atmospheric chemistry is of particular interest in society due to the impact that rising levels of pollutants are having on the climate. It is well-known that combustion processes create CO and NOx, which leads to the creation of other pollutants, such as ozone and CO2. There are natural processes, such as lightning, that also create a significant amount of pollutant gases. The purpose of this guided and open inquiry laboratory experiment is to provide an opportunity for students to investigate how lightning may produce pollutant gases in the atmosphere. In the guided inquiry experiment, a sealed IR gas cell containing air is exposed to a spark or corona discharge created by an Oudin coil to mimic lightning. IR spectroscopy is used to monitor the reaction progress and identify new species made after exposure to the electrical discharge. Based on the results, students draw conclusions about what types of gases are created in the two different discharge processes and how lightning may contribute to atmospheric pollutants. Students move on to the open inquiry to further investigate aspects of atmospheric gases, where they develop their own hypothesis and methods based on one of the provided suggestions, such as the effect of spark and corona discharge on pure oxygen, nitrogen, or carbon dioxide gases, the kinetics of ozone creation and decay, and the temperature dependence of NO2 dimerization. Although designed for an honors general chemistry course, this experiment can be adapted for second-semester general chemistry, environmental chemistry, analytical, and physical chemistry laboratory courses. Results from these experiments are presented, and the relevant atmospheric chemical processes are discussed. The impact of this experiment on perceived gains in knowledge, the value of inclusion in the curriculum, and the design of the experiment were assessed, and the results are discussed.

Creating and testing an activity with interdisciplinary connections: entropy to osmosis

Students often struggle to make interdisciplinary connections and cite a lack of opportunity to make such connections. To address this issue, we are developing activities aligned with the framework of three-dimensional learning that provide students with opportunities to make connections between chemistry concepts and biological phenomena. Here, we focus on an activity that asks students to incorporate the concept of entropy in explaining the biological phenomenon of osmosis across a cell membrane. This activity was administered in both introductory cell and molecular biology and second-semester general chemistry courses. We found that after completing carefully scaffolded questions within the activity, students were better able to correctly use the concept of entropy in explaining osmosis than they were before the scaffolding questions. Additionally, we found that students’ course history appeared to impact their explanations of this phenomenon in that students who had taken second-semester general chemistry (i.e., the semester in which entropy is discussed for these students) provided more sophisticated responses and were less likely to include scientifically inaccurate ideas than their peers who had not taken second-semester general chemistry.

Impact of COVID-19 on General Chemistry Education at the United States Military Academy

The emergence of the novel coronavirus disease-19 (COVID-19) required a rapid shift from in-person instruction to remote learning in our second-semester general chemistry course at the United States Military Academy (USMA), a predominantly undergraduate institution that takes pride in faculty accessibility to students. The decision to conduct remote instruction took effect when students were on spring break; consequently, most students had limited academic resources in hand. This represented a significant paradigm shift for both USMA faculty and students since the institution places an emphasis on in-person engagements with students, as reflected by our low student-to-faculty ratio. We adapted our usual in-person, student-driven instructional method to the remote environment within a 7 day period, which impacted 174 students and six faculty course-wide who were new to the technology, resources, and methodology associated with remote instruction and learning. This communication discusses lessons learned from the transition to asynchronous remote teaching, with a critical focus on the advantages and disadvantages of the adopted teaching methodologies, and includes a discussion of course design and the corresponding adaptions to this new pedagogical environment. We anticipate that these accounts can be leveraged by the broader chemical sciences community to better inform the planning and execution of instruction in future academic terms under remote, in-person, or hybrid (partially remote and partially in-person) environments.

Development of the Reaction Coordinate Diagram Inventory: Measuring Student Thinking and Confidence

The Reaction Coordinate Diagram Inventory (RCDI) has been developed to measure student thinking and confidence with reaction coordinate diagrams (RCDs) and their correspondence to reaction mechanisms. The RCDI was designed using a sequential mixed-methods protocol, such that the questions and distractors in the instrument were generated based on an analysis of qualitative semi-structured interviews in which general chemistry and organic chemistry students were asked to describe the concepts embedded in the surface features of RCDs and to use the mechanistic information encoded in RCDs. The RCDI was administered to second-semester general chemistry students (n = 443), second-semester organic chemistry students (n = 227), and second-semester physical/biophysical chemistry students (n = 45). Descriptive statistics and item function are presented for each of the three samples. Qualitative and quantitative evidence for the validity and reliability of the data generated by the RCDI are also presented. Major categories of misconceptions assessed by the RCDI and data demonstrating the prevalence of these misconceptions for all three groups of students are presented.

The Role of Epistemology and Epistemic Games in Mediating the Use of Mathematics in Chemistry: Implications for Mathematics Instruction and Research on Undergraduate Mathematics Education

Mathematics is used in the physical sciences to describe and model phenomena, resulting in a unique interface between mathematics and disciplines such as chemistry and physics. This paper focuses on themes emerging from a larger project that investigated how students understand and use mathematics in chemical kinetics, a field of study concerned with monitoring the rate of chemical reactions. The primary data source for this study involved a subset of the data from the larger project, focusing on semi-structured interviews with 40 students sampled from a second-semester general chemistry course. During the interviews students were asked to work through chemical kinetics problems that could be solved without calculations (using relationships between quantities and chemistry principles) or they could be solved algorithmically (using equations and the provided data). The interviews were analyzed using the construct of epistemic games, which describe a collection of resources and an associated structure that define and guide problem-solving and reflect epistemological commitments. Findings indicate students have productive resources and approaches for engaging in problem-solving, reflected by the observed shared set of epistemic games. Implications emphasize the role of scaffolding and explicit questioning to prevent compartmentalization of chemistry and mathematics, suggesting the need for more support to help students productively apply the knowledge and skills learned in mathematics courses to contexts such as chemistry.

Impact of arithmetic automaticity on students' success in second-semester general chemistry

Completion of a first-semester chemistry (Chem I) course lays the foundation for understanding second-semester chemistry (Chem II) topics. The purpose of this study is to evaluate the influence of basic arithmetic skills on students’ Chem II success in understanding mathematics-grounded concepts (e.g., solutions and aqueous reactions, kinetics, equilibrium, acids and bases, solubility and equilibria, thermodynamics, electrochemistry, and nuclear chemistry). Previous studies suggest a strong correlation between arithmetic preparation and performance in general chemistry courses, though few have focused on the second-semester course. In this investigation, researchers from six higher-education institutions in Texas, USA of different sizes and with student bodies of different diversities have collaborated to determine whether the Math-Up Skills Test (MUST) is able to reliably identify at-risk students from a population ofn= 1599 at the beginning of a Chem II course.

Introducing randomization tests via an evaluation of peer-led team learning in undergraduate chemistry courses

The methodological limitations education researchers face in the evaluation of reformed instruction have led to debates as to the evidence advancing evidence-based practices. To conduct more effective research, methodological pluralism in the evaluation of educational reforms can be used to complement the strengths and limitations of a corpus of literature informing the impact of an evidence-based practice. This study seeks to introduce randomization tests, a nonparametric statistical analysis incorporating a random-assignment component that can be applied to a single-subject (N = 1) research design, as a methodology to be counted amongst evaluations of instructional reforms. To demonstrate the utility of this approach, an evaluation of peer-led team learning (PLTL) for classes of second-semester general chemistry spanning 7 semesters was conducted using randomization tests. The design contributes novel understandings of PLTL including differences in effectiveness across instructors, trends in effectiveness over time, and a perspective as to the appropriateness of assumptions concerning statistical independence when applied to educational settings. At the research setting, four instructors (each constituting an individual case) alternated implementing lecture-based instruction and PLTL by term. Across these four instructors, the treatment effects of peer-led team learning when compared to lecture-based instruction ranged in impact (from d = 0.233 to 2.09). For two instructors, PLTL provided a means by which to significantly reduce the differential performances observed of students with variable preparations in mathematics, thereby advancing the equitability of their courses. Implications of this work include the incorporation of single-subject research designs in establishing evidence-based instructional practices, the effectiveness of PLTL as interpreted in a methodologically pluralistic context of the research literature, and enacting measurements of equity when gauging the success of instructional reforms in science. Further, this introduction to randomization tests offers another methodology for the evaluation of instructional reforms more widely applicable in educational settings with smaller sample sizes (e.g., reforms conducted within a single classroom or upper-level courses with small class sizes).

Attitudinal and Mathematical Assessments as Measures of Student Success in a College General Chemistry II Course

This study reports results from administering unannounced attitudinal and mathematical assessments to 118 students, at the beginning of the term, in second-semester general chemistry classes (designed for science majors) at Eastern Michigan University. Testing was conducted during the 2010-2011 school year. The question to be answered was: which is more important in determining student course grades, attitudes toward chemistry and mathematics, or mathematical skill? The hypothesis was that attitudes and mathematical skill equally affect final course grade. A modified Wiebe instrument was selected to evaluate student attitudes toward chemistry and mathematics. To evaluate student mathematical skills, this study employed a mathematics assessment developed and performed at the University of Minnesota, and hence will be called the Minnesota Mathematics Assessment or MMA—a 20-question, multiple choice quiz designed for second-semester general chemistry students. Results were inter-correlated to determine what factors influenced student success. This study found a strong correlation between mathematics attitudes and chemistry attitudes, with a Pearson product-moment correlation coefficient (r) of 0.50. Between course grade vs. either chemical attitudes or mathematics attitudes, the r values were 0.25 and 0.23 respectively, showing weak correlations. The correlation of course grade versus total MMA score gave an r value of 0.35, a moderate correlation. Comparison of the current study's MMA results with those of a previous Minnesota study demonstrates that the MMA is reproducible. The correlation coefficient found for course grade vs. total MMA score was comparable to that found in the Minnesota study. Analysis of the 20-question MMA data resulted in a 10-question subgroup whose r = 0.41. Although some gender attitude differences were found, these did not correlate with course grade.

Electroless Deposition on Three Substrates: Brass Washers, Cicada Exoskeletons, and Beetles

This laboratory experiment showcases electroless deposition, an autocatalytic reduction process performed in aqueous solution containing a metal ion in the presence of a reducing agent yielding a coherent metal film. One set of experiments has been performed by second-semester general chemistry students in a 3 h lab session. After preparing an electroless nickel plating bath, they first plate a brass washer with nickel for 10 min at 85 °C. Using weight gain data for their brass washer along with its surface area, the thickness of the nickel coating is determined. The same electroless nickel plating bath is then used to plate a pretreated cicada exoskeleton with nickel. The three-step pretreatment procedure deposits Pd(s) nanoparticles on a nonconducting exoskeleton made of chitin, transforming it into a conducting substrate. A second set of experiments has been performed by upper-class chemistry majors. They (1) explore the reproducibility in weight gain when plating brass washers with nickel for 10, 20, 30, and 40 min time intervals, (2) plate beetles with nickel, and (3) plate cicada exoskeletons with copper using an electroless copper plating bath recipe they find in the literature. Weight gain data and photos of the plated cicada exoskeletons and beetles accompany this article. The nickel-plated brass washers and cicada exoskeletons were examined with XRF spectrometry. This analysis demonstrates that the nickel coating is not pure nickel but rather an alloy containing phosphorus.

ConfChem Conference on Mathematics in Undergraduate Chemistry Instruction: Strengthening Students’ Math Fluencies through Calculator-Free Chemistry Calculations

In our previous study of students in second-semester general chemistry classes at the University of Minnesota, higher scores on a calculator-free math assessment, administered at the start of the semester, were found to correlate with higher grades in this course, despite the use of calculators during exams. The present paper describes some methods subsequently used to enhance students’ math fluency through solving numerical problems using pencil-and-paper math, without the use of a calculator. When doing such problems in class, the instructor can efficiently interleave reminders of basic algebraic methods to simplify expressions, to work with common and natural logs, and to estimate results to one or two significant figures. Multiple-choice exams incorporating problems of this type, in which calculators were not allowed, were also administered. Examples of such problems and their pencil-and-paper solution methods are presented in the areas of chemical equilibrium, acid–base reactions, buffers, and titrat...

Coordinated Implementation and Evaluation of Flipped Classes and Peer-Led Team Learning in General Chemistry

The research-based pedagogical strategy of flipped classes has been shown to be effective for increasing student achievement and retention in postsecondary chemistry classes. The purpose of flipped classes is to move content delivery (e.g., lecture) outside of the classroom, freeing more face-to-face time for active learning strategies. The opportunity to engage in active learning with students can be a challenge for instructors of large classes (more than 100 students). Furthermore, there has been little discussion in the chemical education literature to provide instructors with detailed descriptions of successful implementations of flipped classes combined with active learning in large classes. To this end, this report provides a comprehensive description and evaluation of a coordinated implementation of flipped classes with peer-led team learning (PLTL) for second-semester general chemistry with class sizes greater than 200 students. This approach is described as “Flipped PLTL”. This report includes de...

Experimenting with Synthesis and Analysis of Cationic Gemini Surfactants in a Second-Semester General Chemistry Laboratory

A laboratory experiment is described in which students synthesize a variety of cationic gemini surfactants and analyze their efficacy as fabric softeners. Students perform a simple organic synthesis reaction and two analytical tests (one qualitative and one quantitative), and use the class data to assess the synthesized products. The experiment was based on published research developed in the chemistry department at the institution at which the experiment was developed.

The Development of the Redox Concept Inventory as a Measure of Students’ Symbolic and Particulate Redox Understandings and Confidence

This article describes the development of the Redox Concept Inventory (ROXCI) as a measure of students’ understandings and confidence of both the symbolic and particulate domains of oxidation–reduction (redox) reactions. The ROXCI was created using a mixed-methods design in which the items were developed based upon themes that emerged from the analysis of semi-structured student interviews. The final version of the ROXCI was administered to first- and second-semester general chemistry students post-instruction and post-assessment on redox chemistry. The results include qualitative and quantitative evidence for the content, response process, and association types validity of the data, as well as individual item function and descriptive statistics for each student sample. In conjunction with the validity evidence, reliability was evaluated via a test–retest study. This included the results of the stability of (i) the total scores and average confidence; (ii) the difficulty and discrimination indices per ite...