Chemical kinetics is an important topic that is reinforced across the undergraduate chemistry curriculum, but previous research indicates students tend to have difficulty developing a sophisticated understanding of reaction rate. In this qualitative case study, we characterized how two students conceptualized reaction rate in the context of…

In the resolution of problems in chemical kinetics and catalysis the mathematical models relate the independent variable that is usually time, with the dependent variable which is normally the concentration of a reactant. They conform to linear models, whose parameters such as the ordering to origin and the slope are kinetic parameters, applying…

Herein we present a modified iodine clock experiment which replaces starch with cellulose paper. This provides the reaction with a white solid surface in which color change can be clearly observed and reduces reagent amounts required to 540 µL per group. After data acquisition, students are required to calculate reaction orders and the reaction…

Herein, we present an experience-based learning approach that uses the COVID-19 pandemics knowledge about virus spread and epidemics to establish an analogy between a simple epidemics model--the SIR model (susceptible--infected--removed), and a second-order autocatalytic reaction with subsequent catalyst deactivation. Our approach provides a…

Problem solving is a critical feature of highly quantitative physical science topics, such as chemical kinetics. In order to solve a problem, students must cue into relevant features, ignore irrelevant features, and choose among potential problem-solving approaches. However, what is considered appropriate or productive for problem solving is…

The solution of simple kinetic equations is analyzed without referencing any topic from differential equations or integral calculus. Guided by the physical meaning of the rate equation, a systematic procedure is used to generate an approximate solution that converges uniformly to the exact solution in the case of zero, first, and second order…

We discuss the need for devoting time in differential equations courses to modelling and the completion of the modelling process with efforts to estimate the parameters in the models using data. We estimate the parameters present in several differential equation models of chemical reactions of order n, where n = 0, 1, 2, and apply more general…

This article describes a comprehensive treatment of experimental enzyme kinetics strongly coupled to electronic data acquisition and use of spreadsheets to organize data and perform linear and nonlinear least-squares analyses, all in a manner that promotes development of important reasoning skills. Kinetic parameters are obtained for the stable…

In this paper, we consider solutions to the three-dimensional Schrodinger equation of the form [psi](r) = u(r)/r, where u(0) [is not equal to] 0. The expectation value of the kinetic energy operator for such wavefunctions diverges. We show that it is possible to introduce a potential energy with an expectation value that also diverges, exactly…

Defines and investigates a moment of inertia tensor for a quantum mechanical wave packet. (SL)

Presents a method for simplifying calculations in quantum chemistry by calculating molecular energy from the electrostatic theorem. (SL)

Presents a completely arithmetic development of Newtonian dynamics in which all classical conservation laws are valid and all equations are in forms amenable to high-speed digital computer computation. (SL)

Various examples of open-ended problems and ways to obtain them are presented. Suggestions for incorporating open-ended problems and some of the benefits and difficulties encountered by teachers and students are discussed. Examples are from courses on mass and energy balances, communications, kinetics and ideal reactors, and reactor design. (KR)

Provides a simplified, synoptic overview of the area of thermodynamics, enumerating and explaining the four basic laws, and introducing the mathematics involved in a stepwise fashion. Discusses such basic tools of thermodynamics as enthalpy, entropy, Helmholtz free energy, and Gibbs free energy, and their uses in problem solving. (JM)