On equilibrium properties of aqueous solutions of sulfuric acid, Julius Thomsen has marked that the heat evolved on diluting liquid sulfuric acid with water is a continuous function of the water used, and excluded absolutely the acceptance of definite hydrates as existing in the solution. Information about thermochemical measurement, a discussion…

Conformational analysis of cyclohexanes is a fundamental, requisite topic covered in undergraduate organic chemistry. A molecular modeling experiment is designed with the view of extending students' boundaries of knowledge about cyclohexane conformational stabilities.

The development of a simple spectro photometric method to quantitatively determine the quantity of FD&C color additives present in powdered drink mixes, are focused by the investigations. Samples containing single dyes of binary mixtures of dyes can be analyzed using this method.

Photophysical and photochemical properties of semiconductor metal oxide colloids are studied in the context of photoelectrochemical conversion and storage of solar energy. The experiment teaches the instrumental principles of UV-visible spectrophotometry, spectral acquisition and background subtraction strategies and diode array spectrometers.

The demonstration of sample segregation, which is simple, and visually compelling illustrates the importance of sample handling for students studying analytical chemistry and environmental chemistry. The mixture used in this demonstration has two components, which have big particle size, and different colors, which makes the segregation graphic.

An experiment is described which allows easy, rapid determination of mercury levels in commercially seafood samples from a contaminated area. Students gain experience in the preparation of a calibration curve, the determination of unknown concentrations, and risk assessment based on experimentally determined data.

The study focuses on percarbonate-based stain removers since the percarbonate can be heated to produce additional sodium carbonate. An experiment that provides general chemistry students an opportunity to apply their knowledge of basic stoichiometry to solve a relevant, real-world problem is described.

The role of ethanol O-d in nullifying the deuterolysis may be demonstrated by determining that transesterification of methyl acetoacetate of the ethyl ester occurs as well as deuterium exchange of the five acetoacetate hydrogens. The significant acidity of the methylene protons in the acetoacetate group, the efficacy of base catalysis, the role of…

A multisection undergraduate laboratory involving the microscale synthesis and spectroscopic analysis of unmetalled porphyrins and their corresponding metalloporphyins is described. The microscale synthesis involving the isolation of the metalloporphyrins as solids and their corresponding (super 1)H NMR spectra are presented.

A new undergraduate laboratory experiment suitable for demonstrating some key techniques used in natural products chemistry is described. A laboratory experiment is developed which in the process of extracting shikimic acid from star aniseed exposes students to a number of important experimental techniques.

Electrophilic aromatic substitution (EAS) experiment is designed for the second-semester and undergraduate organic chemistry laboratory. In the EAS experiment, the principles of green chemistry are discussed and illustrated in conjunction with the presentation of electrophilic aromatic substitution.

A chemical laboratory information profile (CLIP) is presented for the chemical, triethanolamine. It summarizes the chemical's physical and harmful features, exposure limits, and symptoms of major exposure for the benefit of teachers and students, who use the chemical in the laboratory.

When students use plants to investigate cellular respiration, they confront the misconception that plants only "perform" photosynthesis (Driver et. al., 1994). Because this is such a strong misconception, several experiences with plant respiration are needed before students accept the idea that plants use some of the food from photosynthesis. Part…

The main goals of these activities are to help students learn how a convex lens can serve as a magnifying lens and how light travels and creates images. These explorations will introduce middle school students to different types of lenses and how they work. Students will observe and describe how lenses bend light that passes through them and how…

In this extended earth science activity, students create a hands-on model of a volcano to achieve an understanding of volcanic structure, lava flows, formation of lava layers, and the scientific work of archaeologists and geoscientists. During this simulation activity, students have opportunities to learn science as inquiry and the nature of…