By adding a large quantity of Cl[superscript -] to an aqueous solution of CoCl[subscript 2][multiplied by]6H[subscript 2]O, a mixture containing a red octahedral cobalt complex and a blue tetrahedral complex is produced. When the solution temperature is modified, the equilibrium constant, K[subscript eq], of the complexation reaction is shifted…

The empirical formulas of four cupric hydrates are determined by measuring the absorbance in aqueous solution. The Beer-Lambert Law is verified by constructing a calibration curve of absorbance versus known Cu[superscript 2+](aq) concentration. A solution of the unknown hydrate is prepared by using 0.2-0.3 g of hydrate, and water is added such…

A convenient laboratory experiment is described in which NMR magnetization transfer by inversion recovery is used to measure the kinetics and thermochemistry of amide bond rotation. The experiment utilizes Varian spectrometers with the VNMRJ 2.3 software, but can be easily adapted to any NMR platform. The procedures and sample data sets in this…

A three-week laboratory experiment, which introduces students in an advanced inorganic chemistry course to air-sensitive chemistry and catalysis, is described. During the first week, the students synthesize RuCl[subscript 2](PPh[subscript 3])[subscript 3]. During the second and third weeks, the students characterize the formed coordination…

Because they are dramatic and intriguing, chemiluminescence demonstrations have been used for decades to stimulate interest in chemistry. One of the most intense chemiluminescent reactions is the oxidation of diaryl oxalate diesters with hydrogen peroxide in the presence of a fluorescer. In typical lecture demonstrations, the commercially…

This qualitative study examined how college science faculty who teach introductory level undergraduate science courses including the fields of chemistry, biology, physics, and earth science, understand and define science and nature of science (NOS). Participants were seventeen science instructors from five different institutions in the…

Some simple chemistry is used to demonstrate how Fe(II) ions, formed during iron corrosion in acid aqueous solution, can reduce toxic Cr(VI) species, forming soluble Cr(III) and Fe(III) ions. These ions, in turn, can be precipitated by neutralizing the solution. The procedure provides a treatment for industrial wastewaters commonly found in…

Many soils throughout the world are contaminated with metal salts of diverse toxicity. We have developed an experiment to demonstrate the removal of a metal from an insoluble surrogate soil pollutant, CuCO[subscript 3] multiplied by Cu(OH)[subscript 2], by complexation followed by the simultaneous electrochemical recovery of the ligand (i.e.,…

Thermotropic liquid crystal phases are ordered fluids found, for some molecules, at intermediate temperatures between the crystal and liquid states. Although technologically important, these materials typically receive little attention in the undergraduate curriculum. Here, we describe a laboratory activity for introductory organic chemistry…

A laboratory experiment aimed at students who are studying coordination chemistry of transition-metal complexes is described. A simple vanadyl acetylacetonate complex can be used as a catalyst in the hydrogen peroxide oxidation of anthracene to produce anthraquinone. The reaction can be performed under a variety of reaction conditions, ideally by…

The physical chemistry laboratory is sometimes constrained to one semester, resulting in pedagogical deficiencies for the students taking the course. The use of a multidimensional laboratory exercise offers students the opportunity to encounter multiple experimental techniques and physical chemistry concepts while not sacrificing a significant…

Educators are increasingly being called upon to provide evidence of student learning. Traditional assessments are not always the best venue for demonstrating conceptual understanding, particularly in science. This paper presents details on the design, use, and scoring of a performance-based assessment for measuring student understanding of…

This study presents the results of an analysis of high school chemistry textbooks and teacher-generated questions about gas laws. The materials that were analyzed consisted of 456 questions about gas laws found in seven grade 10 chemistry textbooks and 264 teacher-generated examination questions prepared by seven chemistry teachers from three…

A procedure for teaching green chemistry through laboratory experiments is presented in which students are challenged to use the 12 principles of green chemistry to review and modify synthesis protocols to improve greenness. A global metric, green star, is used in parallel with green chemistry mass metrics to evaluate the improvement in greenness.…

A method for the construction of a Galilean thermometer out of common chemistry glassware is described. Students in a first-semester physical chemistry (thermodynamics) class can construct the Galilean thermometer as an investigation of the thermal expansivity of liquids and the temperature dependence of density. This is an excellent first…