Caffeine (1,3,7-trimethylxanthine) is an alkaloid stimulant that is popular in beverages. Fluorescence-coupled methods have been used to measure the caffeine content in coffee, tea, soft drinks, energy drinks, and cosmetics. In this experiment, we have developed a method for detecting caffeine in beverages utilizing the effect of the caffeine…

While structure-property relationships are commonly developed in applications of physical organic chemistry to real-world problems at the graduate level, they have not been generally emphasized in the undergraduate chemistry curriculum. For instance, the ability to modify the energy gap between the highest occupied molecular orbital (HOMO) and the…

Quantification of the many constituents that make up our food, whether they are desirable (vitamins, antioxidants, nutrients) or undesirable (pesticides, toxins), is one of the most practical applications of chemistry. In this study, kombucha, a popular fermented tea beverage, was analyzed using acid-base titration and high-performance liquid…

The second law of thermodynamics has various formulations. There is the "Clausius formulation," which can be stated in a very intuitive way: "No process is possible whose sole result is the transfer of heat from a cooler to a hotter body." There is also the "Kelvin-Plank principle," which states that "no cyclic…

The development of novel, high-yielding, and selective methodologies for the asymmetric synthesis of stereocenters is at the forefront of modern synthetic chemistry research. Organocatalysis can now be viewed as a viable alternative to the use of the sometimes toxic transition-metal catalysts. In this experiment, the simple synthesis of an achiral…

In this article, a bomb calorimeter experiment and subsequent calculations aimed at determining the strain energy of the cyclobutane backbone are described. Students use several butanol isomers instead of the parent hydrocarbons, and they manipulate liquids instead of gases, which makes the experiment much easier to perform. Experiments show that…

An undergraduate electrical conductivity measurement experiment in a physical chemistry lab and basic fitting procedures are presented that allow a characterization of micellar system of hexadecyltrimethylammonium bromide (cetyltrimethylammonium bromide, CTAB) in binary mixture of water and acetonitrile (ACN) as a cosolvent (10%, v/v) at 30.0 °C.…

Innovative models of teaching through research have broken the long-held paradigm that core chemistry competencies must be taught with predictable, scripted experiments. We describe here five fundamentally different, course-based undergraduate research experiences that integrate faculty research projects, accomplish ACS accreditation objectives,…

Providing opportunities for science, technology, engineering, and mathematics undergraduates to engage in authentic scientific practices is likely to influence their view of science and may impact their decision to persist through graduation. Laboratory courses provide a natural place to introduce students to scientific practices, but existing…

A series of computer-based laboratory experiments have been developed to aid undergraduate students in appreciating the three-dimensional nature of chemistry and biochemistry. Both lower- and upper-division experiments have been developed. Students are introduced to the use of ChemDraw for the production of professional-quality molecular…

Laboratory work in physics has traditionally focused on the verification of facts, theories and laws. In contrast, this article describes how laboratory tasks can be used to promote students understanding about the nature of science and scientific inquiry. In the project reported here, students learn about measurement uncertainties and a…

The handling of chemicals in the laboratory presents a challenge in instructing large class sizes and when students are relatively new to the laboratory environment. In this work, we describe and demonstrate an augmented reality colorimetric titration tool that operates out of the smartphone or tablet of students. It allows multiple students to…

Students learned the principles and practice of photometry through project-based learning. They addressed the challenge of measuring the unknown concentration of a colored substance using a photometer they were required to design, build, and test. Then, they used that instrument to carry out the experiment and fulfill the challenge. A photometer…

A one-day laboratory epoxidation experiment, requiring no purification, is described, wherein the students are given an "unknown" stereoisomer of 3-hexen-1-ol, and use [superscript 1]H NMR coupling constants to determine the stereochemistry of their product. From this they work backward to determine the stereochemistry of their starting…

Potentiometric titrations are widely taught in first-year undergraduate courses to connect electrochemistry, stoichiometry, and equilibria and to reinforce acid-base titrations. Students perform a potentiometric titration that is then analyzed to determine analyte concentrations and the solubility product constant of the solid species.