NotesFAQContact Us
Collection
Advanced
Search Tips
Showing all 7 results Save | Export
Peer reviewed Peer reviewed
Direct linkDirect link
Halpern, Arthur M.; Noll, Robert J. – Journal of Chemical Education, 2020
The fundamental principles and applications of thermodynamics and single-component phase equilibrium are used to explain and quantitatively analyze the operation and performance of the vapor-compression refrigerator (VCR). Carbon dioxide is used as the refrigerant. The four processes (or steps) that comprise the VCR refrigeration cycle are…
Descriptors: Thermodynamics, Scientific Concepts, Science Instruction, Chemistry
Peer reviewed Peer reviewed
Direct linkDirect link
Halpern, Arthur M.; Noll, Robert J. – Journal of Chemical Education, 2020
The design and operation of the vapor-absorption refrigerator (VAR) are described using the principles and tools typically covered in upper-division undergraduate physical chemistry courses. The objective is to enable students to understand in detail how this device works and how it compares with more typical vapor-compression refrigerators.…
Descriptors: Science Instruction, Chemistry, College Science, Scientific Concepts
Peer reviewed Peer reviewed
Direct linkDirect link
Halpern, Arthur M.; Marzzacco, Charles J. – Journal of Chemical Education, 2018
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…
Descriptors: Chemistry, College Science, Undergraduate Study, Thermodynamics
Peer reviewed Peer reviewed
Direct linkDirect link
Halpern, Arthur M.; Noll, Robert J. – Journal of Chemical Education, 2019
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…
Descriptors: Chemistry, Spreadsheets, Learning Activities, Molecular Structure
Peer reviewed Peer reviewed
Direct linkDirect link
Halpern, Arthur M.; Marzzacco, Charles J. – Journal of Chemical Education, 2018
A spreadsheet-based project is presented that is designed to enhance and expand student understanding of phase transition properties of pure water and ideal and nonideal (electrolyte) aqueous solutions. Using fundamental principles of classical and statistical thermodynamics, students calculate the melting and boiling points, the enthalpies and…
Descriptors: Chemistry, Thermodynamics, Science Instruction, Spreadsheets
Peer reviewed Peer reviewed
Direct linkDirect link
Halpern, Arthur M. – Journal of Chemical Education, 2012
An upper-level undergraduate project is described in which students perform high-level ab initio computational scans of the potential energy curves for Ne[subscript 2] and Ar[subscript 2] and obtain the respective Lennard-Jones (LJ) potential parameters [sigma] and [epsilon] for the dimers. Using this information, along with the summation of…
Descriptors: Chemistry, Science Instruction, College Science, Undergraduate Study
Peer reviewed Peer reviewed
Direct linkDirect link
Halpern, Arthur M. – Journal of Chemical Education, 2010
Using readily available computational applications and resources, students can construct a high-level ab initio potential energy surface (PES) for the argon dimer. From this information, they can obtain detailed molecular constants of the dimer, including its dissociation energy, which compare well with experimental determinations. Using both…
Descriptors: Thermodynamics, Chemistry, Science Instruction, Quantum Mechanics