Quinacridone red and violet are visually different colors, an observation confirmed by their visible reflectance spectra and CIE L*a*b* coordinates. However, their IR spectra are extremely similar. Though chemically identical, the two quinacridones are polymorphs. In this experiment, designed for and tested by nonscience majors, the pigments are…

Mass spectrometry is frequently introduced to undergraduate students as an instrument for both qualitative and quantitative chemical analysis. One of the most common uses of mass spectrometry (MS) is to deduce or confirm a compound's chemical formula, by relying on high-resolution accurate-mass measurements. However, like all forms of instrumental…

Evidence-based reasoning and critical thinking are two crucial scientific abilities of students, sharing a close relationship with each other critical thinking is not just randomly refuting but a logical-reasoning thinking based on solid evidence. However, in real teaching circumstances of experiment classes, students easily directly accept the…

This paper uses evidence-centered assessment design (ECD) to structure and analyze a laboratory activity where students collect and represent titration curve data to determine acid strength in terms of molarity and dissociation constant. Following principles of multidimensional learning, the activity prompts students to demonstrate knowledge of…

Avogadro's conception of the structure of gases was not widely accepted by his contemporaries--probably because the hypothesis was not supported by direct evidence. This problem is rarely addressed in schools. This article discusses the difficulties that accompany the acceptance of new ideas. Such difficulties may be associated with the ways in…

This research study is an investigation of student-laboratory (i.e., lab) learning based on students' perceptions of experiences using questionnaire data and evidence of their science-laboratory performance based on paper-and-pencil assessments using Maryland-mandated criteria, Montgomery County Public Schools (MCPS) criteria, and published…

The use of an internal standard is a conventional and convenient way to monitor the conversion of one or several monomers during a controlled radical polymerization. However, the validity of this technique relies on an accurate determination of the initial monomer-to-internal standard ratio, A[subscript 0], because all subsequent calculations of…

The discipline-based education research (DBER) report from the National Research Council (2012) highlighted the existence of a research-practice gap in science instruction in higher education and the need to identify strategies to close it. This study hypothesizes that one potential factor is instructors' access to research-based…

This laboratory exercise uses a problem-based approach to expose students to some basic concepts relating to proteins and enzymes. One of the main applications of enzymes at the industrial level is their use in the detergent market. The students examine a detergent sample to ascertain whether proteolytic enzymes are a component and, if so, which…

The Science Writing Heuristic (SWH) is an instructional technique that combines inquiry, collaborative learning, and writing to change the nature of the chemistry laboratory for students and instructors. The SWH provides a format for students to guide their discussions, their thinking, and writing about how science activities relate to their own…