A two-week experiment is presented in which students can observe the impact of nanoparticles on the concentration of chlorophyll in plants. First-year students in an introductory nanotechnology laboratory course and a general chemistry laboratory course synthesized silver nanoparticles and then exposed stalks of Egeria densa (E. densa), a common waterweed, to the nanoparticle solution for 1 week. In the following session, students extracted chlorophyll from the plants and measured its concentration using a visible spectrometer. Compared to other, similar lab activities, this experiment generates a lower amount of waste, requires a shorter duration of plant growth, and involves the measurement of chemical species in order to determine the toxicological effects of nanomaterials. Additional ideas are discussed for implementing the experiment in high school, general chemistry, and other courses.Keywords: First-Year Undergraduate/General; Hands-On Learning/Manipulatives; Laboratory Instruction; Nanotechnology;

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.

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.Keywords: Computer-Based Learning; Curriculum; First-Year Undergraduate/General; High School/Introductory Chemistry; Internet/Web-Based Learning; Kinetics; Laboratory Instruction; Oxidation/Reduction; Rate Law;

Periodic illumination and changes in the interfacial aqueous-CFC surface area reveal interesting features of the propagation process occurring during the photoinitiated chain reduction of trichlorofluoromethane (CFC 11) to CHCl2F and Cl– in TiO2 suspensions containing HCO2– ions. Formate ions serve as hole scavengers on the TiO2 surface and react with •CCl2F radicals to form HCCl2F and •CO2–. Carboxyl radicals are capable of propagating the chain reaction in the solution phase by reducing CCl3F. Chain reduction of CCl3F continues after illumination has ceased, and the postirradiation reactions constitute 10% or more of the total Cl– yield. The dark reduction of CFC 11 provides further support to the proposed mechanism in which •CCl2F and •CO2– ions function as chain carriers. The reaction rate measured during a period of illumination is affected by the length of the preceding dark period. In addition, the rate of CCl3F reduction is significantly enhanced by the presence of excess CFC 11, which forms a second, nonaqueous liquid phase. The CCl3F liquid phase in the aqueous, UV irradiated TiO2 suspension increases the photonic efficiency of the reaction by a factor of 4 in both degassed and air saturated systems. Postirradiation reactions occur only in the presence of excess CFC liquid. Kinetic effects of a second liquid phase are a consequence of propagation steps occurring at the water–CCl3F interface with moderately rapid transfer of reactants across the phase boundary. Factors that increase the total surface area of that boundary, such as smaller droplets or greater volume of CCl3F liquid, lead to higher photonic efficiencies.