scholarly journals Correcting Frost Diagram Misconceptions Using Interactive Frost Diagrams

2021 ◽  
Author(s):  
Kaitlyn Dutton ◽  
Mark C. Lipke
Keyword(s):  
Oxidation State ◽  
Thermodynamic Stability ◽  
Redox Conditions ◽  
Oxidation States ◽  
Relative Stabilities ◽  
Conditional Dependence ◽  
Reduction Potentials ◽  
Interactive Diagrams

<p>Frost diagrams provide convenient illustrations of the aqueous reduction potentials and thermodynamic tendencies of different oxidation states of an element. Undergraduate textbooks often describe the lowest point on a Frost diagram as the most stable oxidation state of the element, but this interpretation is incorrect because the thermodynamic stability of each oxidation state depends on the specific redox conditions in solution (i.e., the potential applied by the environment or an electrode). Further confusion is caused by the widespread use of different, contradictory conventions for labeling the y-axis of these diagrams as either n<i>E</i>° or −n<i>E</i>°, among other possibilities. To aid in discussing and correcting these common mistakes, we introduce a series of interactive Frost diagrams that illustrate the conditional dependence of the relative stabilities of each oxidation state of an element. We include instructor’s notes for using these interactive diagrams and a written activity for students to complete using these diagrams.</p>

scholarly journals Correcting Frost Diagram Misconceptions Using Interactive Frost Diagrams

2021 ◽  
Author(s):  
Kaitlyn Dutton ◽  
Mark C. Lipke
Keyword(s):  
Oxidation State ◽  
Thermodynamic Stability ◽  
Redox Conditions ◽  
Oxidation States ◽  
Relative Stabilities ◽  
Conditional Dependence ◽  
Reduction Potentials ◽  
Interactive Diagrams

<p>Frost diagrams provide convenient illustrations of the aqueous reduction potentials and thermodynamic tendencies of different oxidation states of an element. Undergraduate textbooks often describe the lowest point on a Frost diagram as the most stable oxidation state of the element, but this interpretation is incorrect because the thermodynamic stability of each oxidation state depends on the specific redox conditions in solution (i.e., the potential applied by the environment or an electrode). Further confusion is caused by the widespread use of different, contradictory conventions for labeling the y-axis of these diagrams as either n<i>E</i>° or −n<i>E</i>°, among other possibilities. To aid in discussing and correcting these common mistakes, we introduce a series of interactive Frost diagrams that illustrate the conditional dependence of the relative stabilities of each oxidation state of an element. We include instructor’s notes for using these interactive diagrams and a written activity for students to complete using these diagrams.</p>

Stable copernicium hexafluoride (CnF6) with an oxidation state of +VI

2021 ◽  
Author(s):  
Shuxian Hu ◽  
Wenli Zou
Keyword(s):  
Oxidation State ◽  
Oxidation States ◽  
Group 12

As the heaviest group 12 element known now, copernicium (Cn) often presents the oxidation states of +I, +II, and rarely +IV as in its homologue mercury. In this work we...

scholarly journals Selenium– and tellurium–halogen reagents

2018 ◽  
Vol 3 (12) ◽  
Author(s):  
Tristram Chivers ◽  
Risto S. Laitinen
Keyword(s):  
Oxidation State ◽  
Halogen Bond ◽  
The Other ◽  
Oxidation States ◽  
Alkyl Aryl ◽  
Organic Selenium ◽  
Formal Oxidation State ◽  
Wide Range ◽  
Inorganic And Organic

Abstract Selenium and tellurium form binary halides in which the chalcogen can be in formal oxidation states (IV), (II) or (I). They are versatile reagents for the preparation of a wide range of inorganic and organic selenium and tellurium compounds taking advantage of the reactivity of the chalcogen–halogen bond. With the exception of the tetrafluorides, the tetrahalides are either commercially available or readily prepared. On the other hand, the low-valent species, EX2 (E = Se, Te; X = Cl, Br) and E2X2 (E = Se, Te; X = Cl, Br) are unstable with respect to disproportionation and must be used as in situ reagents. Organoselenium and tellurium halides are well-known in oxidation states (IV) and (II), as exemplified by REX3, R2EX2 and REX (R = alkyl, aryl; E = Se, Te; X = F, Cl, Br, I); mixed-valent (IV/II) compounds of the type RTeX2TeR are also known. This chapter surveys the availability and/or preparative methods for these widely used reagents followed by examples of their applications in synthetic inorganic and organic selenium and tellurium chemistry. For both the binary halides and their organic derivatives, the discussion is subdivided according to the formal oxidation state of the chalcogen.

Sorption of trivalent plutonium onto UO2 and the effect of the solid phase on the Pu oxidation state

2005 ◽  
Vol 93 (6) ◽  
Author(s):  
Mattias Olsson ◽  
Henrik Glänneskog ◽  
Anna-Maria Jakobsson ◽  
Hans Nilsson ◽  
Yngve Albinsson
Keyword(s):  
Oxidation State ◽  
Solid Phase ◽  
Oxidation States

SummaryA problem with plutonium in sorption studies is its tendency to occur in a mix of oxidation states. This work was a study of the sorption of plutonium on the solid phase UOA comparison is made between the sorption of Th(IV), Pu(III) and Co(II) on UO

scholarly journals Probing the variability in oxidation states of magnetite nanoparticles by single-particle spectroscopy

2018 ◽  
Vol 6 (4) ◽  
pp. 875-882 ◽  
Author(s):  
A. Fraile Rodríguez ◽  
C. Moya ◽  
M. Escoda-Torroella ◽  
A. Romero ◽  
A. Labarta ◽  
...  
Keyword(s):  
Oxidation State ◽  
Absorption Spectroscopy ◽  
Magnetite Nanoparticles ◽  
Single Particle ◽  
Cation Distribution ◽  
Oxidation States ◽  
Magnetic Response ◽  
X Ray ◽  
Single Particle Spectroscopy ◽  
X Ray Absorption

Single-particle X-ray absorption spectroscopy reveals that the oxidation state and cation distribution of individual magnetite nanoparticles may be largely heterogeneous even when the macroscopic structural and magnetic response of the ensembles is uniform.

scholarly journals Atomic-scale determination of spontaneous magnetic reversal in oxide heterostructures

2019 ◽  
Vol 116 (21) ◽  
pp. 10309-10316 ◽  
Author(s):  
M. Saghayezhian ◽  
Summayya Kouser ◽  
Zhen Wang ◽  
Hangwen Guo ◽  
Rongying Jin ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Charge Transfer ◽  
Oxidation State ◽  
Density Functional ◽  
Magnetic Hysteresis ◽  
Atomic Scale ◽  
Oxidation States ◽  
Internal Electric Field ◽  
Magnetic Reversal ◽  
State Changes

Interfaces between transition metal oxides are known to exhibit emerging electronic and magnetic properties. Here we report intriguing magnetic phenomena for La2/3Sr1/3MnO3 films on an SrTiO3 (001) substrate (LSMO/STO), where the interface governs the macroscopic properties of the entire monolithic thin film. The interface is characterized on the atomic level utilizing scanning transmission electron microscopy and electron energy loss spectroscopy (STEM-EELS), and density functional theory (DFT) is employed to elucidate the physics. STEM-EELS reveals mixed interfacial stoichiometry, subtle lattice distortions, and oxidation-state changes. Magnetic measurements combined with DFT calculations demonstrate that a unique form of antiferromagnetic exchange coupling appears at the interface, generating a novel exchange spring-type interaction that results in a remarkable spontaneous magnetic reversal of the entire ferromagnetic film, and an inverted magnetic hysteresis, persisting above room temperature. Formal oxidation states derived from electron spectroscopy data expose the fact that interfacial oxidation states are not consistent with nominal charge counting. The present work demonstrates the necessity of atomically resolved electron microscopy and spectroscopy for interface studies. Theory demonstrates that interfacial nonstoichiometry is an essential ingredient, responsible for the observed physical properties. The DFT-calculated electrostatic potential is flat in both the LSMO and STO sides (no internal electric field) for both Sr-rich and stoichiometric interfaces, while the DFT-calculated charge density reveals no charge transfer/accumulation at the interface, indicating that oxidation-state changes do not necessarily reflect charge transfer and that the concept of polar mismatch is not applicable in metal−insulator polar−nonpolar interfaces.

Synthesis and hydrolysis of gas-phase lanthanide and actinide oxide nitrate complexes: a correspondence to trivalent metal ion redox potentials and ionization energies

2015 ◽  
Vol 17 (15) ◽  
pp. 9942-9950 ◽  
Author(s):  
Ana F. Lucena ◽  
Célia Lourenço ◽  
Maria C. Michelini ◽  
Philip X. Rutkowski ◽  
José M. Carretas ◽  
...  
Keyword(s):  
Gas Phase ◽  
Metal Ion ◽  
Oxidation States ◽  
Redox Potentials ◽  
Trivalent Metal ◽  
Ionization Energies ◽  
Reduction Potentials ◽  
Hydrolysis Of ◽  
Nitrate Complexes

Gas-phase hydrolysis of lanthanide/actinide MO3(NO3)3−ions relates to the stabilities of the MIVoxidation states, which correlate with IV/III solution reduction potentials and 4th ionization energies.

Oxygen Reduction Effect on T’-Pr2-xCexCuO4 Nanopowders in the Underdoped Regime Studied by X-Ray Absorption near Edge Structure

2018 ◽  
Vol 936 ◽  
pp. 93-97 ◽  
Author(s):  
Irfanita Resky ◽  
Putu Eka Dharma Putra ◽  
Triono Bambang ◽  
Saiyasombat Chatree ◽  
Kamonsuangkasem Krongthong ◽  
...  
Keyword(s):  
Oxidation State ◽  
Oxidation States ◽  
Edge Structure ◽  
X Ray ◽  
Reduction Annealing ◽  
Gas Atmosphere ◽  
Reduction Effect ◽  
Ar Gas ◽  
X Ray Absorption ◽  
Cu Ions

This research is aimed to examine oxidation state of Copper (Cu) in both as-synthesized and reduced T’-Pr2-xCexCuO4 (T’-PCCO) with x = 0, 0.10, and 0.15 using Cu K-edge x-ray absorption near edge structure (XANES). The T‘-PCCO nanopowders were successfully synthesized by the chemically dissolved method with HNO3 as a dissolving agent continued by calcination at 1000°C for 15 h. The reduced T’-PCCO nanopowders were obtained by reduction annealing process at 700°C for 5 h under Ar gas atmosphere. The analyses of XANES spectra show that oxidation states of the Cu ions in all of the T'-PCCO nanopowders have values between +1 and +2. This indicates the existence of electron doping in the CuO2 planes, even in the undoped T’-structure. It is found that the oxidation states of the Cu ions change after reduction annealing depending on the existence of apical oxygen in the T'-structure. Based on the XANES analyses, it is revealed that the change of oxidation state is influenced by the presence of both electron and hole carriers in the two-carrier model of T’-structure.

Notizen: Variety of Oxidation States of Manganese Ions in Compounds with Tripod-Like Tetradentate Ligands

1990 ◽  
Vol 45 (7) ◽  
pp. 1093-1096 ◽  
Author(s):  
Yuzo Nishida ◽  
Miyuki Nasu ◽  
Tadashi Tokii
Keyword(s):  
Oxidation State ◽  
Oxidation States ◽  
Manganese Ions ◽  
Manganese Ion ◽  
Tetradentate Ligands ◽  
Oxo Bridge

From the reaction mixture of Mn(III) acetate and several tripod-like ligands, a Mn(II) complex, a binuclear Mn(III) complex with (μ-oxo)(μ-acetato) core, and a Mn(III)–Mn(IV) complex with a di-μ-oxo bridge were obtained. This demonstrates that the oxidation state of the manganese ion in these compounds is drastically affected by small changes in ligand character.

Actinide and Technetium Solubility Limitations in Groundwaters of Crystalline Rocks

1983 ◽  
Vol 26 ◽  
Author(s):  
B. Allard
Keyword(s):  
Crystalline Rocks ◽  
Solution Chemistry ◽  
Redox Conditions ◽  
Oxidation States ◽  
Reducing Conditions ◽  
As Solubility

ABSTRACTThe solubility and speciation of U, Np, Pu, Am and Tc in deep groundwaters from crystalline rocks have been calculated. The solution chemistry of these elements is largely determined by the redox conditions (Eh = 0.24 − 0.06pH ± 0.06 V, based on measurements of Fe(II)), pH (usually 7 − 9) and the presence of carbonate (log [CO32-] from (pH − 14) to (0.76pH − 10.83), based on measurements of HCO3-). The oxidation states U(IV)(+VI), Np(IV), Pu(III)(+IV), Am(III) and Tc(IV) dominate, with the tetravalent oxides (U, Np, Pu, Tc) and Am2 (CO3)3 (s) as solubility limiting phases. Maximum concentrations in the range 10-9 − 10-10 M or below would be expected for U, Np and Tc under reducing conditions, somewhat higher for Pu and still higher (10-6 − 10-7 M) for Am.

Sign in / Sign up

Export Citation Format

Share Document