Virtual worlds are a potential medium for teaching college-level chemistry laboratory courses. To determine the feasibility of conducting chemistry experiments in such an environment, undergraduate students performed two experiments in the immersive virtual world of Second Life (SL) as part of their regular General Chemistry 2 laboratory course. The experiments’ development and implementation are presented with feedback from students and graduate teaching assistants. Students successfully completed the experiments and showed learning gains similar to students performing real world experiments, as shown by pre/postlab quizzes and a laboratory practicum. Student participants held positive views of their experience in the SL chemistry laboratory. Teaching assistants provided an important perspective about using the virtual world for laboratory instruction. Overall, results of this pilot study suggest that virtual worlds can be effective for teaching chemistry experiments. This is the first account of student learning and attitudes after performing college-level chemistry experiments in the immersive virtual world of SL.

Research projects conducted by faculty in STEM departments served as the inspiration for a new curriculum of inquiry-based, multiweek laboratory modules in the general chemistry 1 course. The purpose of this curriculum redesign was to improve students' attitudes about chemistry as well as their self-efficacy and skills in performing inquiry activities. Students' ability to plan experiments and interpret data improved throughout the semester, as did their confidence in conducting research-like lab activities. Improved confidence was observed among men and women, science and engineering students, and Caucasian and international students. These outcomes are similar to those found with authentic research-based experiments. The curriculum had less of an impact on students' attitudes about chemistry. A research-inspired curriculum offers many benefits to students without the difficulties of designing actual research-based projects for general chemistry classes.

Fluorotrichloromethane (CFC 11) is dehalogenated through a reductive chain reaction upon illumination of aqueous, air-free suspensions of TiO 2 particles in the presence of formate ions. The reduction takes place with large photonic efficiencies at pH g 5 even at high photon fluxes, producing mainly Cland dichlorofluoromethane (HCFC 21), while Fis only a minor byproduct. In the proposed mechanism • CO 2and • CCl 2 F radicals are the chain carriers, Clas well as HCFC 21 result from propagation steps, and crosstermination of the chain carriers forms F -. Simple steady-state assumptions, that regard propagations as the dominant steps, yield kinetic equations consistent with the data of the initial fast Clformation step. The subsequent evolution of rates and postirradiation effects are consequences of the slow removal of electrons from the semiconductor.

A small group of high school students performed a virtual laboratory experiment in Second Life that mimicked a real experiment in both its appearance and procedure. Lab report grades were equivalent to report grades for hands-on experiments, and the quality of students’ results was similar. Results of an attitudinal survey show that students expressed similarly favorable views of the hands-on and virtual experiments, and they found that report writing was equally challenging for both types of experiments. The virtual experiment required significantly less time to complete. The quality of the students’ results and their responses to the survey demonstrate that a laboratory exercise in Second Life may be a feasible alternative to an experiment in a real laboratory setting.

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Chlamydomonas reinhardtii (Cr), a unicellular alga, is routinely utilized to study photosynthetic biochemistry, ciliary motility, and cellular reproduction. Its minimal culture requirements, unicellular morphology, and ease of transformation have made it a popular model system. Despite its relatively slow doubling time, compared with many bacteria, it is an ideal eukaryotic system for microplate-based studies utilizing either, or both, absorbance as well as fluorescence assays. Such microplate assays are powerful tools for researchers in the areas of toxicology, pharmacology, chemical genetics, biotechnology, and more. However, while microplate-based assays are valuable tools for screening biological systems, these methodologies can significantly alter the conditions in which the organisms are cultured and their subsequent physiology or morphology. Herein we describe a novel method for the microplate culture and in vivo phenotypic analysis of growth, viability, and photosynthetic pigments of C. reinhardtii. We evaluated the utility of our assay by screening silver nanoparticles for their effects on growth and viability. These methods are amenable to a wide assortment of studies and present a significant advancement in the methodologies available for research involving this model organism.

Abstract. The results of the heterogeneous photocatalytic reduction of Fe(VI) in UV-irradiated TiO 2 suspensions are presented and suggest indirect observation of the formation of Fe(V) by the photoreduction of Fe(VI) with e cb − at TiO 2 surfaces. Because Fe(V) selectively and rapidly oxidizes low reactivity pollutants with the production of the non-toxic by-product, Fe(III), the photocatalytic reduction of Fe(VI) has a role in pollution remediation processes. The experiments were conducted as a function of TiO 2 suspension concentrations, Fe(VI) concentrations, and pH in basic media. The initial rate of Fe(VI) reduction gave a fractional order with respect to initial Fe(VI) concentrations and adheres to simple Langmuir-Hinshelwood kinetics.Results suggest that the surface reaction (Fe(VI) + e cb − → Fe(V)) is the rate-controlling step. The photocatalytic reduction of Fe(VI) in the presence of less reactive nitrogen-containing species (ammonia, cyanate, and fulvic acid) were also investigated. Enhancement in the rate of Fe(VI) reduction was observed. A reaction scheme involving Fe(V) as an intermediate is presented which explains the faster photocatalytic oxidation of pollutants in the presence of Fe(VI).