The American Statistical Association’s GAISE Report on introductory statistics for college students should serve as a model for thinking about introductory chemistry courses.

Over the course of three semesters, the tutorials for introductory organic chemistry at McGill University evolved significantly with the input from student surveys. The tutorials changed from “chalk talks” in the first semester to a lecture capture format in the second in which PowerPoint slides, ink annotations, and associated audio were recorded, and uploaded online to be viewable by any student at any time. As expected, the later format reached more students, though fewer came in person to the live tutorial. In an effort to continue to reach as many students as possible, while at the same time providing a more engaging environment for students at the live event, the format changed once more. Demonstrations, discussions, and other personalized interactions not accessible online were incorporated in the third semester to provide a more meaningful experience for students physically present, without compromising the online content. This third tutorial format in the final semester did indeed encourage more students to come in person. Herein, we follow the evolution of these tutorials, discuss the impetus for changing formats, document student use (both online and in person) and conclude that lecture capture technology is an effective means of delivering optional course content and it can be effectively supplemented by demonstrations and other personalized interactions to reach students with different learning styles.

In a recent article in this Journal, Quílez concludes that a sound introduction to the Gibbs energy may be too difficult for first-year students to understand. In this letter, the author indicates how the specified problems can be eliminated.

Many of the instruments developed for research use by the chemistry education community are relatively new. Because psychometric evidence dictates the validity of interpretations made from test scores, gathering and reporting validity and reliability evidence is of utmost importance. Therefore, the purpose of this study was to investigate what “counts” as psychometric evidence within this community. Using a methodology based on concepts described and operationalized in the Standards for Educational and Psychological Testing, instruments first published in the Journal between 2002 and 2011, and follow-up publications reporting the use of these instruments, were examined. Specifically, we investigated the availability of evidence based on test content, response processes, internal structure, relations to other variables, temporal stability, and internal consistency. Findings suggest that our peer review and reporting practices value some types of evidence while neglecting others. Results of this study serve as an indication of the need for the chemistry education research community to view gathering psychometric evidence as a collective activity and to report such evidence at the level of detail appropriate to inform future research.

The Chemical Concepts Inventory (CCI) is a multiple-choice instrument designed to assess the alternate conceptions of students in high school or first-semester college chemistry. The instrument was published in 2002 along with an analysis of its data from a test population. This study supports the initial analysis and expands on the psychometric data available. The CCI was given to over 2500 students from four universities. Data were analyzed using classical test theory and Rasch model methods. The classical test theory analysis found the CCI to have acceptable internal consistency (Cronbach’s α = 0.73, pretest, and 0.76, posttest) and good test–retest reproducibility (Pearson correlation = 0.79, posttest). Most items were found to have good difficulty and discrimination values; however, a few had values that may warrant further evaluation. The Rasch analysis showed that the instrument and the items nicely fit the Rasch model. The data showed good separation reliability and that the instrument overall is at an appropriate level for the population. However, several gaps were found along the range of item difficulties, leading to less accurate estimations of student abilities. Overall, the CCI was found to be suitable for the large-scale assessment of students’ alternate conceptions.

This study was designed to evaluate the effects of a proprietary software program on students’ conceptual and visual understanding of dimensional analysis. The participants in the study were high school general chemistry students enrolled in two public schools with different demographics (School A and School B) in the Chattanooga, Tennessee, metropolitan area. Using a “treatment group” and a “control group” (no treatment), a mixed-methods design was used in the data collection and analysis to provide a holistic view of the impact of the software on student learning. The resulting qualitative and quantitative data confirmed that the software enhanced the treatment groups’ conceptual and visual understanding of dimensional analysis. In fact, when all of the quantitative and qualitative data were viewed as a whole, the advantages of integrating use of the software into the general chemistry classroom proved to have significant impact on student conceptual and visual understanding of dimensional analysis. The enhanced conceptual understanding was verified by quantitative data, which indicated a significant difference between the overall pretest and posttest scores of the treatment group (n = 14, t = −2.896, p = 0.008). On the basis of the descriptive statistics, it is evident that all students benefited from using the software. The qualitative data showed that students’ visual understanding was enhanced and that they valued their experiences using the software and were able to enhance their knowledge of all aspects of dimensional analysis. The researcher takes the lessons learned from this study and provides practical best practices on effectively integrating elements of the software to enhance conceptual and visual understanding in traditional chemistry classrooms.

As is true for virtually all of higher education, chemistry departments are often required to provide evidence of student learning at both course and curricular levels through evaluation and assessment. The ACS Exams Institute conducted a needs assessment survey of 1500 chemistry faculty members from across the country to investigate motivation, role, instrument use, and challenges associated with assessment efforts. For the more than 70% of participants who reported departmental efforts related to assessment, these findings emerged: motivations were primarily external factors related to accreditation and certification, ACS Exams and in-house exams were the most common instruments used, and time management associated with grading and reporting assessment results was the most frequently cited challenge. Summary results for each survey question related to these aspects of departmental assessment efforts are provided, along with logistic regression analyses of responses based on institution type. Logistic regression analyses were also used to identify differences among sex, years teaching, and chemistry subdiscipline for responses to departmental assessment efforts and instrument use.

An introductory, nonscience-majors chemistry course was converted to a Web-based course. The differences in student populations, teaching strategies, laboratory methods, and learning outcomes are described. Practical information is also given on the use of software and other online technology to implement course conversion.

Thirty-six pre-university chemistry students and two chemistry teachers used flow chemistry as a technology for the synthesis of methyl orange. FutureChemistry and VU University Amsterdam cooperatively created FlowStart Remote, a device that enabled the students to remotely conduct this synthesis and in real time monitor and control the device via a LabVIEW Web application. The students were able to conduct experiments under different conditions and became acquainted with flow chemistry in a safe way. The remotely controlled device can be shared among several upper-level secondary schools, giving access to experimentation for many students all over the world.

Education institutions globally are increasingly expected to explore avenues for the implementation of service-learning into their curricula. A second-year undergraduate organic chemistry laboratory experiment, in which the undergraduate students make azo dyes, can provide a vehicle for a service-learning module in which university undergraduate students then teach students from resource-limited secondary schools how to make azo dyes. Evidence is provided to show how the theory is reinforced for both sets of students through a shared practical experience. The practical application of chemistry is conveyed through the use of the synthetic azo dyes to dye t-shirts. The results of this study show that the service-learning experience clearly assists undergraduate students to appreciate the role of chemists in the broader society while at the same time increasing awareness of the inequalities in school education systems.

Starting with the fundamental and general criterion for a spontaneous process in thermodynamics, ΔS_tot ≥ 0, we review its relationships to other criteria, such as ΔA and ΔG, that have limitations. The details of these limitations, which can be easily overlooked, are carefully explicated. We also bring in the important example of electrical energy to show how criteria for spontaneity are properly applied to electrochemical cells. The analysis in this article gains clarity from use of the “global” formulation of thermodynamics and from carrying out finite changes of thermodynamic properties rather than manipulating differential changes. Several examples are given.

Several educators have advocated teaching thermodynamics using a “global” approach in place of the conventional “local” approach. This article uses four examples of experiments to illustrate the two formulations and the definitions of heat and work associated with them. Advantages and disadvantages of both approaches are discussed. The article concludes that either formulation can be used for conceptual understanding of the first and second laws of thermodynamics, that the local formulation is usually less complicated, and that the choice of a formulation for evaluating thermodynamic quantities from experimental measurements depends on the experiment.

For physical measurements, the compositions of solutions, especially electrolyte solutions, are expressed in terms of molality rather than mole fractions. The development of the necessary thermodynamic equations directly in terms of molality is not common in textbooks, and the treatment in the literature is not very systematic. We develop a methodical treatment of this topic and define a new reference solution that can be used for solutions whose composition is described in terms of molality. Thermodynamic quantities per mass of solvent appear naturally in the derivation. We discuss how these quantities may be used to analyze experimental data.

A simple method is presented for the consecutive determination of protonation constants of polyprotic acids based on their formation curves. The procedure is based on generally known equations that describe dissociation equilibria. It has been demonstrated through simulation that the values obtained through the proposed method are sufficiently consistent with the actual values. In contrast with the universally known and applied Bjerrum’s method, no differences in the accuracy of determination of subsequent protonation constant values are observed. The proposed method requires the value of one of the protonation constants (e.g., of the first one, K₁) of the polyprotic acid. An iterative method is proposed for finding the value, starting from approximate values determined from the environment of point n̅ = 0.5(n̅-average degree of protonation). Apart from high accuracy, the proposed method also has didactic advantages because it illustrates the problem of multiple acid equilibria in a visual (almost graphic) manner. The proposed method may also provide initial constant values for numerical methods of nonlinear approximation of the formation curve.

A systematic way to understand the intricacies of quantum mechanical computations done by a software package known as “Gaussian” is undertaken via an undergraduate research project. These computations involve the evaluation of key parameters in a fitting procedure to express a Slater-type orbital (STO) function in terms of the linear combination of Gaussian-type orbital (GTO) functions. A procedure for the optimization process based on the Newton–Raphson method is developed and is applied to STO-2G and STO-3G basis sets. Satisfactory results obtained by this procedure are used to illustrate the importance of ab initio computations for inclusion in the chemistry or physics undergraduate curriculum. Programming languages such as Python and Maple were employed to obtain the results.

The hydrogenation of alkenes by heterogeneous catalysts has been studied for 80 years. The foundational mechanism was proposed by Horiuti and Polanyi in 1934 and consists of three steps: (i) alkene adsorption on the surface of the hydrogenated metal catalyst, (ii) hydrogen migration to the β-carbon of the alkene with formation of a σ-bond between the metal and α-C, and finally (iii) reductive elimination of the free alkane. Hundreds of papers have appeared on the topic, along with a number of variations on the Horiuti–Polanyi mechanism. The second step is highly reversible, leading to extensive deuterium–hydrogen exchange when D₂(g) is used. This paper describes the investigation of gas-phase reactions between deuterium and 1-butene using a supported palladium catalyst under ambient laboratory conditions and how the results are consistent with the Horiuti–Polanyi mechanism. An Excel spreadsheet for modeling the extent and distribution of deuteration within butane-d_x is described. Interested readers could develop a laboratory or research experience based on results presented here. The results are also suitable for inclusion in an upper-division chemistry course in which organometallic chemistry or reaction mechanisms involving heterogeneous catalysts are discussed. The catalyst tubes are inexpensive and easy to construct. Analysis of the butane produced by ¹H NMR and GC–MS leads to numerous conclusions in support of the Horiuti–Polanyi mechanism.

Catalysis with transition-metal complexes is a part of the inorganic chemistry curriculum and a challenging topic for upper-level undergraduate and graduate students. A hands-on teaching aid has been developed for use during conventional lectures to help students understand these catalytic reactions. A unique method of illustrating the coordination polymerization of propylene with interlocking building blocks is described. Three metallocene block models mimicking real catalysts recognize top and bottom faces of a prochiral propylene monomer block model and subsequently provide three polypropylene structures with different tacticity. The monomer recognition processes of the metallocene block models are based on steric hindrance, similar to those of the real catalysts.

By using cardboard models that resemble propellers, the students of inorganic courses can easily visualizing the distinct rotation of optical isomers. These propellers rotate clockwise or counterclockwise when they are dropped from a certain height or in the presence of wind.

A visual demonstration of the difference between hydrophilic and hydrophobic surfaces has been developed. It involves placing a shadow mask on an optically clear hydrophobic plastic dish, corona treating the surface with a modified Tesla coil, removing the shadow mask, and visualizing the otherwise invisible message or pattern by applying water, thus entitled as hydroglyphics.

Household items coated with various metals or titanium compounds can be heated to produce colorful films with nanoscale thicknesses.

Drawing a schematic energy diagram for the decomposition of H₂O₂ catalyzed by MnO₂ through a simple thermometric measurement outlined in this study is intended to integrate students’ understanding of thermochemistry and kinetics of chemical reactions. The reaction enthalpy, Δ_rH, is determined by a conventional thermometric method, where a modified calorimetric vessel with negligible thermal leakage is used. Thermometric curves for the reactions at different initial temperatures can be converted to different series of kinetic rate data under nonlinearly changing temperatures. The apparent activation energy, E_a, is easily determined by the differential kinetic relationship at the fixed degree of reaction among the different series of kinetic rate data. By determination of both Δ_rH and E_a, students can draw a schematic diagram of the energy change accompanying the reaction. The laboratory activity and post lab data treatments are useful in general chemistry courses at the university or college level and also applicable in advanced chemistry courses in high schools.

A laboratory inquiry into the thermochemical relationships in the reaction between aqueous solutions of NaHCO₃ and NaOH is described. The enthalpy change for this reaction, Δ_rH, and that for neutralization of strong acid and NaOH(aq), Δ_nH, are determined calorimetrically; the explanation for the difference is the basis for the student inquiry. The contribution of acid dissociation of the hydrogen carbonate ion to the overall reaction is considered by students as a possible explanation for the difference. Using Hess’s law, students propose a positive value for the acid dissociation enthalpy change Δ_dH. Then, they are required to show experimental evidence of the positive Δ_dH. Examination of the temperature dependence of the acid dissociation constant K_a is performed by students through pH measurements of the solution at the half-neutralization point of the reaction between aqueous solutions of NaHCO₃ and NaOH at different temperatures. This provides a second means of predicting the sign of Δ_dH; then, through introduction of the van’t Hoff equation, a numerical value for Δ_dH can be calculated. The goal of the inquiry activity is to verify Hess’s law using the evaluated experimental values of Δ_rH, Δ_nH, and Δ_dH. This lab activity is appropriate for advanced chemistry courses at high schools or general chemistry courses at colleges. Further, calculations of the Gibbs energy change Δ_dG and entropy change Δ_dS of acid dissociation of the hydrogen carbonate ion from the student data for the temperature dependence of K_a can be applied in an advanced lab activity.

The thermodynamic properties of weak acid ionization reactions are determined. The thermodynamic properties are corresponding values of the absolute temperature (T), the weak acid equilibrium constant (K_a), the enthalpy of ionization (Δ_iH°), and the entropy of ionization (Δ_iS°). The enthalpy of ionization (Δ_iH°) is determined from the enthalpy of neutralization of HCl(aq) and the enthalpy of neutralization of the weak acid by application of Hess’s law; NaOH(aq) is the base. A datalogger and a temperature sensor (±0.01 °C sensitivity) are used to measure and plot the thermograms of the reactions. The calorimeter constant (C_Cal) is determined by electrical heating of the post-reaction solution; procedure takes 10–20 s for each C_Cal determination. With NaOH(aq) as the limiting reagent, the post-reaction solutions consist of a weak acid and corresponding conjugate base allowing K_a to be determined from the measured pH of these solutions. The values of T, K_a, and Δ_iH° are used to calculate Δ_iS° according to the equation: Δ_iG° = −RT ln K_a = Δ_iH° – TΔ_iS°. The choice of H₃PO₄(aq), a triprotic weak acid, provides an opportunity for students to predict and explain expected trends in K_a, Δ_iH°, and Δ_iS° prior to their determination. The multiconcept nature of this lab exercise makes it an ideal capstone laboratory exercise in general chemistry.

The essential oil of Nepeta cataria L. (catnip), an herbaceous plant known popularly as a stimulant for the domestic cat, is enriched in two diastereomeric iridoid lactones (nepetalactones) that vary in ratio. Although the diastereomers are chromatographically separable and exhibit different 1D NMR spectra, it is not possible to differentiate between them chromatographically or spectroscopically without previous knowledge or more complex NMR experiments; however, the trans-fused lactone readily epimerizes to the thermodynamically more stable cis-fused lactone upon treatment with base. Students in the introductory organic laboratory establish the presence of the two major nepetalactones in catnip essential oil by TLC and GC–MS analysis, assigning TLC spots and GC peaks to specific lactones by chromatographic comparison of the essential oil with the product of epimerization (i.e., cis-fused lactone) and determining the diastereomeric ratio of nepetalactones by GC peak integration.

A computational experiment that investigates single-walled carbon nanotubes (SWNTs) has been developed and employed in an upper-level undergraduate physical chemistry laboratory course. Computations were carried out to determine the electronic structure, radial breathing modes, and the influence of the nanotube’s diameter on the curvature-induced strain. The students used a new graphical user interface to the TubeGen nanotube builder, which we have implemented as an extension to the open-source molecular editor Avogadro, to build and visualize SWNTs. Geometry optimizations, molecular orbital calculations, and frequencies were computed by an external quantum chemical program.

A computational experiment that investigates the optical activity of the amino acid valine has been developed for an upper-level undergraduate physical chemistry laboratory course. Hybrid density functional theory calculations were carried out for valine to confirm the rule that adding a strong acid to a solution of an amino acid in the l configuration renders the optical rotation more positive. Correspondingly, if the optical rotation becomes more negative, the amino acid is of the d configuration. The students employed the open-source molecular editor Avogadro to build the molecules, conduct conformer searches, and calculate the energies of the conformers with a molecular mechanics force field. Subsequent geometry optimizations and optical rotation calculations were performed with a quantum chemistry program, using the WebMO graphical interface. The role of the solvent in stabilizing the zwitterionic form of an amino acid was investigated.

An undergraduate exercise in computational chemistry that investigates the energy barrier for pyramidal inversion of amines and phosphines is presented. Semiempirical calculations (PM3) of the ground-state and transition-state energies for NR¹R²R³ and PR¹R²R³ allow for the determination of the activation energy for pyramidal inversion. Various factors affecting the inversion activation energy are considered. The exercise can be done easily in a 3-h lab on a standard laptop running Spartan or Spartan Student or as a homework assignment.

Computational chemistry undergraduate laboratory courses are now part of the chemistry curriculum at many universities. However, there remains a lack of computational chemistry exercises available to instructors. This exercise is presented for students to develop skills using computational chemistry software while supplementing their knowledge of physical organic chemistry, specifically Hammett plots. Students use quantum calculations to determine the gas-phase Gibbs energy of ionization of substituted benzoic acids and phenols to generate a theoretical Hammett plot, thereby familiarizing themselves with the application of computational chemistry to physical organic chemistry.

Wave functions for rotating diatomic molecules (spherical harmonics) were three-dimensionally visualized by using Graph-R in tandem with Excel.

Students in chemistry lectures were encouraged to use Twitter.com to ask and answer questions during and after lectures. Across 12 lectures, 49 students from a total enrollment of 485 generated 112 messages, of which 68% were germane to the course. Among users and nonusers alike, 77% reported Twitter made it easier to ask questions, but 66% also reported the messages intruded on lectures.

Some recent successes connecting with and tracking chemistry alumni using the social networking sites Facebook and LinkedIn are described. This communication provides tips on how to develop digital alumni networking sites, offers ideas on content, and reports on their effectiveness and will be of interest to any chemistry faculty member who is interested in increasing their department’s ability to connect with and track alumni.

This piece traces the early origins of the stereochemical line and wedge symbolism and its entry into the organic textbook in the 1960s. It also comments on inconsistencies in its textbook usage and current debates over its use in representing absolute configurations.