We report one teacher's response to a top-down shift from external examinations to internal teacher assessment for summative purposes in the Republic of Ireland. The teacher adopted a comparative judgement approach to the assessment of secondary students' understanding of a chemistry experiment. The aims of the research were to investigate whether…

This study examines how students perceive their learning of creating and analyzing data in an introductory inquiry chemistry course at a college level that features oral presentations in student-centered discussions. A student Participant Perception Indicator (PPI) survey was administered in order to obtain data on student perceptions with respect…

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…

The study reported here was conducted to investigate the perceptions of high school students on the use of educational games as a tool for teaching the periodic table of elements in a chemistry class in Spain. The 127 students who participated in this study came from six different classes in grade 10 (15-16 years old). The students' perceptions of…

In this exploratory study, students in four co-taught high school chemistry classes were randomly assigned to a Universal Design for Learning (UDL) treatment or a comparison condition. Each co-teaching team taught one comparison and treatment class. UDL principles were operationalized for treatment: (a) a self-management strategy (using a…

An undergraduate experiment on coulometric analysis of four commercial household products is presented. A special type of coulometry cell made of polydimethylsiloxane (PDMS) polymer is utilized. The PDMS cell consists of multiple analyte compartments and an internal network of salt bridges. Experimental procedure for the analysis of the acid in a…

In this paper, we describe a new method we have developed for setting cut scores between levels of a test. We outline the wide variety of potential methods that have been used for such a process, and emphasize the need for a coherent conceptual framework under which the variety of methods could be understood. We then describe our particular…

This article describes the work being undertaken to make more use of supercritical carbon dioxide as a green solvent. It discusses how the use of surfactants can address the limitations of supercritical CO[subscript 2] in dissolving solutes that are polar and of higher molecular weight. The design of appropriate hydrocarbon CO[subscript 2]-philic…

Perfluorocarbons (PFCs) are fully fluorinated hydrocarbons that are used as blood plasma substitutes, in medical imaging and in the cosmetics industry. Most are inert and can also be used as tracers for applications such as air flow. However, because of their C-F bonds and their longevity in the atmosphere, PFCs have large global warming…

This paper describes the Assessment Practices Framework and how I used it to study a high school Chemistry teacher as she designed, implemented, and learned from a chemistry lab report. The framework consists of exploring three teacher-centered components of classroom assessment (assessment beliefs, practices, and reflection) and analyzing…

The Moffitt-Woodward-Moscowitz-Klyne-Djerassi octant rule is one of the most successful empirical rules in organic chemistry. However, the lack of a simple effective modeling method for the octant rule in the past 50 years has posed constant difficulties for researchers, teachers, and students, particularly the young generations, to learn and…

A proposal to define the oxidation state of an atom in a compound as the hypothetical charge of the corresponding atomic ion that is obtained by heterolytically cleaving its bonds such that the atom with the higher electronegativity in a bond is allocated all electrons in the bond. Bonds between like atoms are cleaved homolytically. This…

The well-known colorimetric determination of the equilibrium constant of the iron(III-thiocyanate complex is simplified by preparing solutions in a cuvette. For the calibration plot, 0.10 mL increments of 0.00100 M KSCN are added to 4.00 mL of 0.200 M Fe(NO[subscript 3])[subscript 3], and for the equilibrium solutions, 0.50 mL increments of…

Ethylenediaminetetraacetate (EDTA) is commonly used as an anticoagulant in blood-collection procedures. In this experiment for the instrumental analysis laboratory, students determine the quantity of EDTA in commercial collection tubes by coulometric titration with electrolytically generated Cu[superscript 2+]. The endpoint is detected…

The teaching of two-component phase diagrams has attracted little attention in this "Journal," and it is hoped that this article will make a useful contribution. Current physical chemistry textbooks describe two-component phase diagrams adequately, but do so in a piecemeal fashion one section at a time; first solid-liquid equilibria, then…