Analytical Chemistry of Molybdenum and Tungsten


Book Description

International Series of Monographs in Analytical Chemistry, Volume 47: Analytical Chemistry of Molybdenum and Tungsten describes the chemical and instrumental methods of analysis of molybdenum and tungsten. This book is composed of 15 chapters that particularly consider detailed methods for determining these metals in typical samples and their alloys by both classical and modern techniques. The opening chapters discuss the history, occurrence, physico-chemical properties, and applications of molybdenum and tungsten. The succeeding chapters deal with the metals’ sampling, decomposition, separation, and qualitative detection. Considerable chapters are devoted to various chemical and instrumental methods for their analysis, including gravimetry, titrimetry, colorimetry, polarography, amperometry, coulometry, emission and atomic absorption spectroscopy, X-ray spectrophotometry, mass spectrometry, and radiochemical methods. The concluding chapter examines the determination of impurities and alloying elements. This book will prove useful to analytical and inorganic chemists, as well as analytical and inorganic chemistry students.




The Chemistry of Chromium, Molybdenum and Tungsten


Book Description

The Chemistry of Chromium, Molybdenum and Tungsten deals with the chemistry of chromium, molybdenum, and tungsten. The discovery and history, occurrence and distribution, and production of all three elements are discussed, along with their industrial uses, preparation, and allotropes; nuclear, physical, and chemical properties; biological activities; and analytical chemistry. Organized into three sections, this volume begins with an overview of the history, occurrence and distribution, and production of chromium, molybdenum, and tungsten, as well as their industrial uses, preparation, and allotropes; nuclear, physical, and chemical properties; biological activities; and analytical chemistry. The intermetallic phases in binary alloys of all three elements are also considered, along with their oxidation states and respective compounds including compounds with non-metallic elements; compounds of ?-acceptor ligands; organometallic complexes; and peroxy compounds such as peroxychromates, tetraperoxy molybdates, and peroxy tungstates. This book will be of interest to inorganic chemists as well as students and researchers in the field of inorganic chemistry.







Tungsten Complexes


Book Description




Molybdenum and Tungsten Enzymes


Book Description

There has been enormous progress in our understanding of molybdenum and tungsten enzymes and relevant inorganic complexes of molybdenum and tungsten over the past twenty years. This set of three books provides a timely and comprehensive overview of the field and documents the latest research. Building on the first and second volumes that focussed on biochemistry and bioinorganic chemistry aspects, the third volume focusses on spectroscopic and computational methods that have been applied to both enzymes and model compounds. A particular emphasis is placed on how these important studies have been used to reveal critical components of enzyme mechanisms. This text will be a valuable reference to workers both inside and outside the field, including graduate students and young investigators interested in developing new research programs in this area.




Effects of Interstitial Impurities on the Low-temperature Tensile Properties of Tungsten


Book Description

A study was undertaken to determine the effects of the interstitial impurities oxygen and carbon on the mechanical properties of polycrystalline tungsten and high-purity tungsten single crystals. Results of tensile tests showed that additions of both oxygen and carbon to polycrystalline tungsten produced a marked increase in the ductile to brittle transition temperature. Oxygen and carbon produced a much smaller increase in the transition temperature of the single-crystal specimens compared with equivalent amounts of impurities in the polycrystalline specimens. Addition of oxygen to polycrystalline tungsten lowered both the ultimate tensile strength and the yield strength, but had no measurable effect on the strength properties of single-crystal specimens. Carbon additions to both polycrystalline and single-crystal specimens did not affect the ultimate tensile strength; however, a large increase in the yield strength resulted. The results suggest that oxygen embrittlement in tungsten is caused by grain-boundary segregation, while carbon embrittlement results from an interaction between carbon atoms and dislocations within the tungsten lattice.




Oxidation of Tungsten


Book Description

The report presents a detailed review of available information on the oxidation of W and its alloys. W is relatively inert below 700 C. As the temperature is increased above this level, however, oxidation becomes progressively more rapid, reaching catastrophic rates at temperatures around 1200 C and above. Various theories for the mechanism and rates of W oxidation at different temperatures are reviewed, and the effect of pressure and water vapor on the stability of W oxides is discussed in detail. The elevatedtemperature reactions of W with other materials, such as refractory oxides, and with gases other than oxygen also are covered. Information on the protection of W by alloying and coating is included. (Author).




Transition Metal Sulphides


Book Description

Hydrotreating catalysis with transition metal sulphides is one of the most important areas of industrial heterogeneous catalysis. The present book deals with the chemical and catalytic aspects of transition metal sulphides, focusing on their use in hydrotreating catalysis. The book¿s 12 chapters present reviews of solid-state, coordination and organometallic chemistry, surface science and spectroscopic studies, quantum chemical calculations, catalytic studies with model and real catalysts, as well as refinery processes. A presentation of state-of-the-art background to pertinent work in the field. Can be used as an introduction to the chemical and catalytic properties of transition metal sulphides as well as an advanced level reference.




Molybdenum and Tungsten Enzymes


Book Description

This book covers the bioinorganic chemistry of molybdenum and tungsten enzymes and the physicochemical methods that are used to investigate their structure and function.




Chemistry Of Transition Elements


Book Description

Contents: The Properties of Transition Elements, Titanium, Zirconium and Hafnium Group IV A, Vanadium, Niobium and Tantalum Group V A, Chromium, Molybdenum and Tungsten Group VI A, Manganese, Technetium and Rhenium Group VII A, Iron, Cobalt and Nickel, The Platinum Metals, Copper, Silver and Gold Group IB, Analytical and Biological Aspects of Transition Metals, Coordination Compounds, Lanthanides & Actinides.