All analytical techniques are governed by the principles of physical chemistry, and chromatography is certainly no exception. By examining the underlying concepts of size exclusion chromatography (SEC), students can gain greater appreciation of and insight into the science and utility of thermodynamics, as well as solution properties of…

A method for using electronic structure calculations to predict the standard molar enthalpy of combustion for hydrocarbons is presented. In this approach, simple geometry optimizations can be used to accurately compute the enthalpy of combustion within 3% of the experimental value using Hartree-Fock, MP2, or virtually any functional in density…

In the laboratory, data acquisition systems are important, as they allow us to easily and precisely collect data. In this sense, Arduino emerges as an automatic data acquisition device with great potential, due to its low cost and high versatility. In this work, we describe the development of an experimental apparatus, with automatic data…

A spreadsheet project that enables students to construct chemical potential vs temperature plots, [mu](T), of liquid and gaseous mercury and all three phases of diiodine and ammonia is presented. Statistical thermodynamics is used to determine the entropies of the substances in the gas phase. For the solid and liquid phases, students start with…

The change in enthalpy of a chemical reaction conducted at constant pressure is equal to the heat of the reaction plus the nonexpansion work of the reaction, ?H = qP + w[subscript additional]. After deriving that relationship, most general and physical chemistry textbooks set w[subscript additional] = 0 to arrive at the claim that ?H = qP, and…

A spreadsheet-based exercise for students is described in which they are challenged to explain and reproduce the disparate temperature dependencies of the heat capacities of gaseous F[subscript 2] and N[subscript 2]. For F[subscript 2], C[subscript p,m] increases from 300 K, reaches a maximum at 2200 K, and then decreases to 74% of the maximum…

A newly developed laboratory learning program for high school chemistry courses is discussed, in which students discover the chemical mechanism governing exothermic phenomena during the reaction between a heating agent, namely, calcium oxide (CaO)--aluminum (Al) mixture, and water. Based on prior knowledge of simple heating agents such as CaO, the…

This study focuses on designing a laboratory learning program for a high school chemistry course in which students could discover the fundamental principles of Hess's law via stepwise inquiry. By exploring the chemical properties of common desiccants, mainly those that were reactive in water, students were introduced to the exothermic reaction of…

With the development of a strong bioeconomy sector related to the creation of next-generation biorefineries, heterogeneous catalysis is receiving renewed attention. Indeed, catalysis is at the core of biorefinery design, and many new catalysts and catalytic processes are being developed. On the one hand, they are based on knowledge acquired during…

In the laboratory experiment described here, students synthesize silver nanostructures (AgNS) with different shapes and sizes to elucidate the shape- and size-dependent optical properties of nanostructured materials. Students also develop understanding of some thermodynamic and kinetic aspects of the synthesis process through this experiment. In…

Connecting the thermodynamic definition of entropy, dS = dQ/T (Clausius's equation), with the statistical definition, S = k[subscript B] ln [omega] (Boltzmann's equation), has been a persistent challenge in chemical education at the undergraduate level. Not meeting this challenge results in students taking away the meaning of entropy in a vague…

Heat and enthalpy are challenging topics for general chemistry students because they are conceptually complex and require avariety of quantitative problem-solving approaches. Expert chemists draw on conditional knowledge, deciding when and under what conditions a certain problem-solving approach should be used. Decision-based learning (DBL)…

In this article, we use a simple lattice model to illustrate the concepts of entropy, free energy, and thermodynamic equilibrium from a microscopic perspective. These physical concepts are based on elementary knowledge of discrete probability distribution and weighted average. Calculations about this model involve basic algebra and counting, which…

Two-dimensional nuclear magnetic resonance (2D NMR) techniques are regularly used for the determination of RNA structures. In an effort to introduce advanced level students who are generally not acquainted with or exposed to these techniques, this work, which has been designed as a practicum, utilizes a combination of 2D NMR techniques to help…

Thermodynamic characterization of micelle formation from an ionic surfactant in aqueous solutions is a classic experiment in physical chemistry. The critical micelle concentration (CMC) and the degree of micelle ionization ([alpha)] can be directly obtained by conductimetry, then thermodynamic parameters ([delta]G[subscript m][superscript o],…