The applications of zinc oxide powder are numerous, and the principal ones are summarized below. Most applications exploit the reactivity of the oxide as a precursor to other zinc compounds. For material science applications, zinc oxide has high refractive index, high thermal conductivity, binding, antibacterial and UV-protection properties. Consequently, it is added into materials and products including plastics, ceramics, glass, cement, rubber, lubricants, paints, ointments, adhesive, sealants, concrete manufacturing, pigments, foods, batteries, ferrites, fire retardants, etc.
Applications
Zinc oxide
Zinc oxide | Applications
It is used for making plastics, ceramics, glass, cement, rubber, lubricants, paints, ointments, adhesive, sealants, concrete manufacturing, pigments, foods, batteries, ferrites, fire retardants, etc. It is used as an additive in numerous materials and products including cosmetics, food supplements, rubbers, plastics Leavening agent For material science applications, zinc oxide has high refractive index, high thermal conductivity, binding, antibacterial and UV-protection properties.
describe in general terms the structure of ionic solids such as nacl
user
Ions typically pack into extremely regular crystalline structures, in an arrangement that minimizes the lattice energy.
assistant
what can you tell me about their boiling point?
user
Boiling points exhibit similar trends to melting points in terms of the size of ions and strength of other interactions. When vapourized, the ions are still not freed of one another.
assistant
can you name any compounds?
user
Ammonium acetate, zinc oxide, aluminum hydroxide,  aluminium oxide and lead(II) oxide.
assistant
what are the uses of the aforesaid initial one?
user
It is also used as a diuretic.
assistant
what can you tell me about its production?
user
Ammonium acetate is produced by the neutralization of acetic acid with ammonium carbonate or by saturating glacial acetic acid with ammonia.
assistant
what are the applications of the second one?
user
Industrial applications include wood preservation, manufacturing other zinc salts, polymers, manufacture of ethyl acetate, as a dye mordant, and analytical reagent. It is used in commercial nuclear power plants as a plating inhibitor on primary water piping.
Zinc acetate | Industrial applications
A small amount of industrial production involves wet chemical processes, which start with aqueous solutions of zinc salts, from which zinc carbonate or zinc hydroxide is precipitated. The solid precipitate is then calcined at temperatures around 800 °C.
Zinc oxide | Wet chemical process
In the second one-pot operation, trifluoroacetic acid is employed first to deprotect the "tert"-butyl ester of (6); any excess reagent was removed via evaporation. The carboxylic acid produced as a result of the deprotection was then converted to an acyl chloride by oxalyl chloride and a catalytic amount of DMF. Finally, addition of sodium azide, in the last reaction of the second one-pot operation, produce the acyl azide (7) without any purification needed.
Oseltamivir total synthesis | Hayashi Synthesis
The monoaquo complex Zn(acac)HO (m.p. 138–140 °C) is pentacoordinate, adopting a square pyramidal structure. The complex is of some use in organic synthesis. Dehydration of this species gives the hygroscopic anhydrous derivative (m.p. 127 °C). This more volatile derivative has been used as a precursor to films of ZnO.
Metal acetylacetonates | Zinc triad
Ammonium acetate is produced by the neutralization of acetic acid with ammonium carbonate or by saturating glacial acetic acid with ammonia. Obtaining crystalline ammonium acetate is difficult on account of its hygroscopic nature.
Ammonium acetate | Production
Thin films can be produced by chemical vapor deposition, metalorganic vapour phase epitaxy, electrodeposition, pulsed laser deposition, sputtering, sol-gel synthesis, atomic layer deposition, spray pyrolysis, etc. Ordinary white powdered zinc oxide can be produced in the laboratory by electrolyzing a solution of sodium bicarbonate with a zinc anode. Zinc hydroxide and hydrogen gas are produced. The zinc hydroxide upon heating decomposes to zinc oxide.
Zinc oxide | Laboratory synthesis
Second was the investigation of new ways to produce ammonium nitrate. Freeth built upon his pre-war work and implemented two processes he had devised in 1909 at an industrial scale in plants at Lostock Gralam, Sandbach and a specialised factory in Swindon. For his work during the war, he was appointed an OBE in 1924.
Francis Arthur Freeth | World War I
The second method entails hydrolysis of trichloroethylene:
Chloroacetic acid | Production
The applications of zinc oxide powder are numerous, and the principal ones are summarized below. Most applications exploit the reactivity of the oxide as a precursor to other zinc compounds. For material science applications, zinc oxide has high refractive index, high thermal conductivity, binding, antibacterial and UV-protection properties. Consequently, it is added into materials and products including plastics, ceramics, glass, cement, rubber, lubricants, paints, ointments, adhesive, sealants, concrete manufacturing, pigments, foods, batteries, ferrites, fire retardants, etc.
Zinc oxide | Applications
Furthermore, changes to the reagents such as the use of chloroform instead of carbon tetrachloride can form additional products.
Zincke–Suhl reaction | Applications
Heating Zn(CHCO) in a vacuum results in a loss of acetic anhydride, leaving a residue of basic zinc acetate, with the formula ZnO(CHCO). This cluster compound has the tetrahedral structure shown below. This species closely resembles the corresponding beryllium compound, although it is slightly expanded with Zn-O distances ~1.97 vs ~1.63 Å for BeO(OAc).
Zinc acetate | Basic zinc acetate
After neutralization, only the zinc stays in solution while germanium and other metals precipitate. After removing some of the zinc in the precipitate by the Waelz process, the residing Waelz oxide is leached a second time. The dioxide is obtained as precipitate and converted with chlorine gas or hydrochloric acid to germanium tetrachloride, which has a low boiling point and can be isolated by distillation:
Germanium | Production
A more convenient and cheaper method proceeds by treatment of zinc powder with hydrochloric acid and copper(II) sulfate. Treatment of zinc powder with copper(II) acetate monohydrate in hot acetic acid is reportedly highly reproducible. The couple may also be generated in situ by reaction of one equivalent of zinc dust with one equivalent of copper(I) chloride (or copper powder) in refluxing ether. The choice of method is dictated primarily by the application. The development of newer methods was motivated by the need for zinc–copper couple with reproducible behavior.
Zinc–copper couple | Synthesis
The New Jersey Zinc process is no longer used to produce primary zinc in the U.S., in Europe and Japan, however it still is used to treat secondary operations. This process peaked in 1960, when it accounted for 5% of world zinc production. A modified version of this process is still used at Huludao, China, which produced 65,000 metric tons per year. This process begins by roasting concentrates that are mixed with coal and briquetted in two stages. The briquettes are then heated in an autogenous coker at and then charged into the retort. There are three reasons to briquette the calcine: to ensure free downward movement of the charge; to permit heat transfer across a practical size cross-section; to allow adequate porosity for the passage of reduced zinc vapour to the top of the retort.
Zinc smelting | New Jersey Zinc continuous vertical retort
Zinc nitrate has no large scale application but is used on a laboratory scale for the synthesis of coordination polymers. Its controlled decomposition to zinc oxide has also been used for the generation of various ZnO based structures, including nanowires. It can be used as a mordant in dyeing. An example reaction gives a precipitate of zinc carbonate:
Zinc nitrate | Applications
In the second reaction sequence, [Carbonyl-14C]-2-hydroxy-acetophenone was used first. Compound XII was formed from condensation of [carbonyl-14C-]-2-hydroxy-acetophenone with dimethyl oxylate and ring closure. Hydrogenolytical debenzylation and hydrochloric acid created the final product.
Repinotan | Second Reaction Scheme
The mechanism of the Wolff–Kishner reduction has been studied by Szmant and coworkers. According to Szmant's research, the first step in this reaction is the formation of a hydrazone anion 1 by deprotonation of the terminal nitrogen by MOH. If semicarbazones are used as substrates, initial conversion into the corresponding hydrazone is followed by deprotonation. A range of mechanistic data suggests that the rate-determining step involves formation of a new carbon–hydrogen bond at the carbon terminal in the delocalized hydrazone anion. This proton capture takes place in a concerted fashion with a solvent-induced abstraction of the second proton at the nitrogen terminal.
Wolff–Kishner reduction | Mechanism
In one solid-phase synthesis application, the amine is covalently attached to Wang resin. Another example is the synthesis of a chiral isoquinolinium salt.
Zincke reaction | Applications
It contains a polymeric anion (ZnCl) with balancing monohydrated hydronium ions, HO ions. The formation of highly reactive anhydrous HCl gas formed when zinc chloride hydrates are heated is the basis of qualitative inorganic spot tests. The use of zinc chloride as a flux, sometimes in a mixture with ammonium chloride (see also Zinc ammonium chloride), involves the production of HCl and its subsequent reaction with surface oxides. Zinc chloride forms two salts with ammonium chloride: (NH)ZnCl and (NH)ClZnCl, which decompose on heating liberating HCl, just as zinc chloride hydrate does. The action of zinc chloride/ammonium chloride fluxes, for example, in the hot-dip galvanizing process produces H gas and ammonia fumes.
Zinc chloride | Reactions
V(acac) is a common precatalyst for the production of EPDM polymers. It has also been shown to be a precursor to vanadium pentoxide nanostructures.
Vanadium(III) acetylacetonate | Applications and research
The direct or American process starts with diverse contaminated zinc composites, such as zinc ores or smelter by-products. The zinc precursors are reduced (carbothermal reduction) by heating with a source of carbon such as anthracite to produce zinc vapor, which is then oxidized as in the indirect process. Because of the lower purity of the source material, the final product is also of lower quality in the direct process as compared to the indirect one.
Zinc oxide | Direct process
Copper(II) acetate is prepared industrially by heating copper(II) hydroxide or basic copper(II) carbonate with acetic acid.
Copper(II) acetate | Synthesis
This produces zinc sulfide, together with large amounts of hot gas, heat, and light.
Zinc | Other industrial uses
One major use is as an absorbent in surgical dressings. It is also used to find zinc salts by mixing sodium hydroxide with the suspect salt.
Zinc hydroxide | Applications
Prior to the commercialization of the Monsanto process, most acetic acid was produced by oxidation of acetaldehyde. This remains the second-most-important manufacturing method, although it is usually not competitive with the carbonylation of methanol. The acetaldehyde can be produced by hydration of acetylene. This was the dominant technology in the early 1900s. Light naphtha components are readily oxidized by oxygen or even air to give peroxides, which decompose to produce acetic acid according to the chemical equation, illustrated with butane: Such oxidations require metal catalyst, such as the naphthenate salts of manganese, cobalt, and chromium. The typical reaction is conducted at temperatures and pressures designed to be as hot as possible while still keeping the butane a liquid.
Acetic acid | Acetaldehyde oxidation
ZnBr · 2HO is prepared by treating zinc oxide or zinc metal with hydrobromic acid. The anhydrous material can be produced by dehydration of the dihydrate with hot CO or by reaction of zinc metal and bromine.
Zinc bromide | Production
Zinc ammonium chloride is the inorganic compound with the formula (NH)ZnCl. It is the ammonium salt of tetrachlorozincate. It used as a flux in the process of hot-dip galvanizing.
Zinc ammonium chloride | Introduction
Zinc oxide (ZnO) reacts with both acids and with bases: This reactivity can be used to separate different cations, such as zinc(II), which dissolves in base, from manganese(II), which does not dissolve in base. Lead oxide (PbO): Aluminium oxide (AlO)
Amphoterism | Amphoteric oxides
Molecular zinc(II) hydride, ZnH, was recently identified as a volatile product of the acidified reduction of zinc ions with sodium borohydride. This reaction is similar to the acidified reduction with lithium aluminium hydride, however a greater fraction of the generated zinc(II) hydride is in the molecular form. This can be attributed to a slower reaction rate, which prevents a polymerising concentration of building over the progression of the reaction. This follows earlier experiments in direct synthesis from the elements. The reaction of excited zinc atoms with molecular hydrogen in the gas phase was studied by Breckenridge "et al" using laserpump-probe techniques.
Zinc hydride | Molecular form
The thermochemical two-step water splitting process uses redox systems: For the first endothermic step concentrating solar power is used in which zinc oxide is thermally dissociated at into zinc and oxygen. In the second non-solar exothermic step zinc reacts at with water and produces hydrogen and zinc oxide. The temperature level is realized by using a solar power tower and a set of heliostats to collect the solar thermal energy.
Zinc–zinc oxide cycle | Process description
The hydrates, especially the heptahydrate, are the primary forms used commercially. The main application is as a coagulant in the production of rayon. It is also a precursor to the pigment lithopone. It is also used as an electrolyte for zinc electroplating, as a mordant in dyeing, and as a preservative for skins and leather.
Zinc sulfate | Manufacturing
The remainder (< 5%) is used in personal care, institutional, commercial products and for unique patented uses such as photography.
Amine oxide | Applications
Gallium oxide thin films can be produced by atomic layer epitaxy (ALE) by combining gallium acetylacetonate with either water or ozone as the precursor. Ga(acac) can also be used for low temperature growth of high purity gallium nitride nano-wires and nano-needles.
Gallium acetylacetonate | Uses
In addition, the finely dispersed carbon poses a risk of explosion. For these reasons and due to its low acidity, magnesium oxide has proven to be a good alternative. Carriers with acidic properties extract electrons from ruthenium, make it less reactive, and undesirably bind ammonia to the surface.
Haber process | Second generation catalysts
Ball and roller bearings also began being used in machinery. Other important alloys are used in high temperatures, such as steam turbine blades, and stainless steels for corrosion resistance.
Second Industrial Revolution | Applied science
A D Wilson and J W Nicholson, Acid-Base Cements, 1993, , Chapter 9
Zinc oxide eugenol | References
By weight, most of the world's zinc oxide is manufactured via French process.
Zinc oxide | Indirect process
Lead acetate can be made by boiling elemental lead in acetic acid and hydrogen peroxide. This method will also work with lead carbonate or lead oxide. Pb(s) + HO(aq) + 2 H(aq) → Pb(aq) + 2 HO(l) Pb(aq) + 2 CHCOO(aq) → Pb(CHCOO)(aq) Lead(II) acetate can also be made via a single displacement reaction between copper acetate and lead metal:
Lead(II) acetate | Production
Major applications of zinc include (numbers are given for the US)
Zinc | Applications
Roughly one quarter of all zinc output in the United States in 2009 was consumed in zinc compounds; a variety of which are used industrially. Zinc oxide is widely used as a white pigment in paints and as a catalyst in the manufacture of rubber to disperse heat. Zinc oxide is used to protect rubber polymers and plastics from ultraviolet radiation (UV). The semiconductor properties of zinc oxide make it useful in varistors and photocopying products. The zinc zinc-oxide cycle is a two step thermochemical process based on zinc and zinc oxide for hydrogen production. Zinc chloride is often added to lumber as a fire retardant and sometimes as a wood preservative.
Zinc | Other industrial uses
In the indirect or French process, metallic zinc is melted in a graphite crucible and vaporized at temperatures above 907 °C (typically around 1000 °C). Zinc vapor reacts with the oxygen in the air to give ZnO, accompanied by a drop in its temperature and bright luminescence. Zinc oxide particles are transported into a cooling duct and collected in a bag house. This indirect method was popularized by LeClaire (France) in 1844 and therefore is commonly known as the French process. Its product normally consists of agglomerated zinc oxide particles with an average size of 0.1 to a few micrometers.
Zinc oxide | Indirect process
The zinc–zinc oxide cycle or Zn–ZnO cycle is a two step thermochemical cycle based on zinc and zinc oxide for hydrogen production with a typical efficiency around 40%.
Zinc–zinc oxide cycle | Introduction
Steel to be galvanized passes through an acidic cleaning process to remove iron oxide "mill scale". After this process, the surface of the steel is very active and oxide layers begin forming immediately upon exposure to the atmosphere. Zinc ammonium chloride flux in aqueous solution is applied to the steel to reduce any oxides that are formed and/or inhibit them from forming altogether. This allows the molten zinc in the proceeding galvanizing step to maximally adhere to and alloy with the surface of the steel.
Zinc ammonium chloride | Uses
The final product produced by this mechanism is therefore a 3-oxy-substituted 2"H"-indazole. Slight variations of this mechanism exists depending on the starting materials and the conditions (acid or base) of the reaction. In instances of intramolecular oxygen attack (i.e. step 5 of the proposed mechanism is intramolecular) an "o"-nitrobenzylidene imine intermediate is formed compared to the secondary imine of the displayed mechanism. Furthermore, Davis–Beirut reactions in acids form a carbocation as one of its transition states instead of the proposed carbanion one when the reaction occurs in base.
Davis–Beirut reaction | Mechanism in base
This second film element is used to create a matte, as well as a counter-matte, for use during compositing on an optical printer. These complementary mattes allow the various image elements to be cleanly isolated, so that as they are re-exposed onto a single, fresh piece of negative, one at a time and in jigsaw fashion, the various images do not show through one another (as they would using simple double exposure). Acquiring the matte film element (as a first-generation original) at the same time as the live action makes a much better fit during optical printing, because it requires fewer separate, duplicate film generations than does bluescreen (though both processes degrade the image and introduce more "error" to the resulting matte) in the process of achieving sufficiently dense mattes.
Sodium vapor process | Introduction
It is produced by thermal reactions of compounds of the type HNCHCHX (X = OH, NH, or NHR) in the presence of zeolitic catalysts. An idealized conversion is shown for the conversion from ethanolamine:
DABCO | Production
The optional second step (for bare silicon wafers) is a short immersion in a 1:100 or 1:50 solution of aqueous HF (hydrofluoric acid) at 25 °C for about fifteen seconds, in order to remove the thin oxide layer and some fraction of ionic contaminants. If this step is performed without ultra high purity materials and ultra clean containers, it can lead to recontamination since the bare silicon surface is very reactive. In any case, the subsequent step (SC-2) dissolves and regrows the oxide layer.
RCA clean | Second step (optional): oxide strip
Those properties are valuable in emerging applications for: transparent electrodes in liquid crystal displays, energy-saving or heat-protecting windows, and electronics as thin-film transistors and light-emitting diodes.
Zinc oxide | Introduction
Nevertheless, the molecular mechanism of nitrite oxidation is an open question.
Nitrifying bacteria | Second step nitrification - molecular mechanism
Zinc oxide-eugenol may present as a powder (zinc oxide) that requires mixing with a liquid (eugenol). The zinc oxide powder may contain up to 8% of other zinc salts (acetate, propionate, or succinate) as accelerators. The liquid containing eugenol has up to 2% of acetic acid added as an accelerator. A well-known product utilised in this powder-liquid form is Kalzinol™.
Luting agent | Zinc oxide-eugenol
In anhydrous zinc acetate the zinc is coordinated to four oxygen atoms to give a tetrahedral environment, these tetrahedral polyhedra are then interconnected by acetate ligands to give a range of polymeric structures. In contrast, most metal diacetates feature metals in octahedral coordination with bidentate acetate groups. In zinc acetate dihydrate the zinc is octahedral, wherein both acetate groups are bidentate.
Zinc acetate | Basic properties and structures
The Romans produced considerable quantities of brass (an alloy of zinc and copper) as early as 200 BC by a cementation process where copper was reacted with zinc oxide. The zinc oxide is thought to have been produced by heating zinc ore in a shaft furnace. This liberated metallic zinc as a vapor, which then ascended the flue and condensed as the oxide. This process was described by Dioscorides in the 1st century AD. Zinc oxide has also been recovered from zinc mines at Zawar in India, dating from the second half of the first millennium BC. From the 12th to the 16th century zinc and zinc oxide were recognized and produced in India using a primitive form of the direct synthesis process.
Zinc oxide | History
Zinc nitrate is usually prepared by dissolving zinc in nitric acid, this reaction is concentration dependent, with a reaction in concentrated acid also forming ammonium nitrate: On heating, it undergoes thermal decomposition to form zinc oxide, nitrogen dioxide and oxygen.
Zinc nitrate | Synthesis and reactions
Zinc acetate is a salt with the formula Zn(CHCO), which commonly occurs as the dihydrate Zn(CHCO)·2HO. Both the hydrate and the anhydrous forms are colorless solids that are commonly used in chemical synthesis and as dietary supplements. Zinc acetates are prepared by the action of acetic acid on zinc carbonate or zinc metal. When used as a food additive, it has the E number E650.
Zinc acetate | Introduction
The common synthesis method is the "Wislicenus process", which proceeds in two steps from ammonia. In the first step, ammonia is converted to sodium amide: The sodium amide is subsequently combined with nitrous oxide: These reactions are the basis of the industrial route, which produced about 250 tons per year in 2004, with production increasing owing to the popularization of airbags.
Sodium azide | Preparation
ZnO has also been considered for spintronics applications: if doped with 1–10% of magnetic ions (Mn, Fe, Co, V, etc.), ZnO could become ferromagnetic, even at room temperature. Such room temperature ferromagnetism in ZnO:Mn has been observed, but it is not clear yet whether it originates from the matrix itself or from secondary oxide phases.
Zinc oxide | Spintronics
Hydrochloric acid and hydrobromic acid are oxidised to the corresponding halogen, e.g., Vanadates or vanadyl compounds in acid solution are reduced by zinc amalgam through the colourful pathway: [[File:Vanadium oxidation states.jpg|none|300px|thumb|
Vanadium(V) oxide | Other redox reactions
The former contains the Zn(NH) ion , and the latter is molecular with a distorted tetrahedral geometry. The species in aqueous solution have been investigated and show that Zn(NH) is the main species present with Zn(NH)Cl also present at lower NH:Zn ratio. Aqueous zinc chloride reacts with zinc oxide to form an amorphous cement that was first investigated in the 1855 by Stanislas Sorel. Sorel later went on to investigate the related magnesium oxychloride cement, which bears his name. When hydrated zinc chloride is heated, one obtains a residue of Zn(OH)Cl e.g. The compound ZnCl·HCl·HO may be prepared by careful precipitation from a solution of ZnCl acidified with HCl.
Zinc chloride | Reactions
Amalgamated zinc is first prepared by treating zinc metal with a 2% solution of mercury(II) chloride, in a beaker. The metal may be in the granulated form or as shavings, wool, or 20-30 mesh powder. The mercury ions are able to penetrate the passive layer and are reduced to elemental mercury, forming the amalgam, which is a kind of alloy of both metals, on the metal surface. The amalgam is thoroughly washed by decantation and placed in a long glass tube, similar to a chromatography column, equipped with a stopcock and a means to support the amalgam, such as a sintered-glass disk.
Jones reductor | Preparation and use
The primary use of acetic acid is the production of vinyl acetate monomer (VAM). In 2008, this application was estimated to consume a third of the world's production of acetic acid. The reaction consists of ethylene and acetic acid with oxygen over a palladium catalyst, conducted in the gas phase. Vinyl acetate can be polymerised to polyvinyl acetate or other polymers, which are components in paints and adhesives.
Acetic acid | Vinyl acetate monomer
However, this production process has not been used again industrially after the end of the war, because of high associated costs. For commercial use a cheaper method starting from acetylene has been used. First, nitric acid containing mercuric nitrate is reduced by acetylene, resulting in trinitromethane (nitroform) and a mixture of carbon dioxide and nitrogen oxide as waste gas. The nitrogen oxides are valuable and normally recovered as nitric acid in an absorption tower. The resulting nitroform is converted to TNM by adding nitric and sulfuric acid at higher temperatures. With this method a yield of 90% (based on nitric acid) before purification can be reached.
Tetranitromethane | Preparation
Uranyl zinc acetate has been used as a catalyst for converting dimethyl carbonate into toluene-2,4-diisocyanate (TDI).
Uranyl zinc acetate | Laboratory use
The second solution is switching to another vapor pressure equation with more than three parameters. Commonly used are simple extensions of the Antoine equation (see below) and the equations of DIPPR or Wagner.
Antoine equation | Example calculation
Numerous specialised methods exist for producing ZnO for scientific studies and niche applications. These methods can be classified by the resulting ZnO form (bulk, thin film, nanowire), temperature ("low", that is close to room temperature or "high", that is T ~ 1000 °C), process type (vapor deposition or growth from solution) and other parameters. Large single crystals (many cubic centimeters) can be grown by the gas transport (vapor-phase deposition), hydrothermal synthesis, or melt growth. However, because of high vapor pressure of ZnO, growth from the melt is problematic. Growth by gas transport is difficult to control, leaving the hydrothermal method as a preference.
Zinc oxide | Laboratory synthesis
2-Naphthylamine is prepared by heating 2-naphthol with ammonium zinc chloride to 200-210 °C, the Bucherer reaction. It also can be produced its acetyl derivative by heating 2-naphthol with ammonium acetate to 270-280 °C.
2-Naphthylamine | Preparation
The resulting dithiophosphate is then neutralized by adding zinc oxide:
Zinc dithiophosphate | Synthesis and structure
Amalgamated zinc is a powerful reducing agent, with a standard redox potential of −0.76 V. The amalgam does not have a passive layer so it is a more effective reducing agent than zinc metal. The Jones reductor is useful for preparing solutions of titanium(III), vanadium(II), chromium(II), molybdenum(III), niobium(III) and uranium(III). All these ions are extremely susceptible to oxidation. For example, the reductor can be used in the preparation of crystalline chromous acetate. This solid is moderately stable in air and is a good starting material for the preparation of other chromium(II) compounds.
Jones reductor | Applications
This review cited studies that found lower plasma zinc concentrations in the subjects who consumed zinc oxide and zinc carbonate than in those who took zinc acetate and sulfate salts. For fortification, however, a 2003 review recommended cereals (containing zinc oxide) as a cheap, stable source that is as easily absorbed as the more expensive forms. A 2005 study found that various compounds of zinc, including oxide and sulfate, did not show statistically significant differences in absorption when added as fortificants to maize tortillas.
Zinc | Dietary intake
Acetic acid is mildly corrosive to metals including iron, magnesium, and zinc, forming hydrogen gas and salts called acetates: Because aluminium forms a passivating acid-resistant film of aluminium oxide, aluminium tanks are used to transport acetic acid. Metal acetates can also be prepared from acetic acid and an appropriate base, as in the popular "baking soda + vinegar" reaction: A colour reaction for salts of acetic acid is iron(III) chloride solution, which results in a deeply red colour that disappears after acidification. A more sensitive test uses lanthanum nitrate with iodine and ammonia to give a blue solution. Acetates when heated with arsenic trioxide form cacodyl oxide, which can be detected by its malodorous vapours.
Acetic acid | Reactions with inorganic compounds
Manganese(II) acetate can be formed by treating either manganese(II,III) oxide or manganese(II) carbonate with acetic acid:
Manganese(II) acetate | Reactions
The second type includes nucleophillic addition-elimination reactions, such as the alkaline hydrolysis of ethyl acetate:
Rate equation | Second order
Ceramic industry consumes a significant amount of zinc oxide, in particular in ceramic glaze and frit compositions. The relatively high heat capacity, thermal conductivity and high temperature stability of ZnO coupled with a comparatively low coefficient of expansion are desirable properties in the production of ceramics. ZnO affects the melting point and optical properties of the glazes, enamels, and ceramic formulations. Zinc oxide as a low expansion, secondary flux improves the elasticity of glazes by reducing the change in viscosity as a function of temperature and helps prevent crazing and shivering. By substituting ZnO for BaO and PbO, the heat capacity is decreased and the thermal conductivity is increased.
Zinc oxide | Ceramic industry
This study was the first time that carbon and nitrogen isotope ratios were directly measured at a sub-cellular scale in a biological sample.
Nanoscale secondary ion mass spectrometry | Biological Applications
In another modality, a ‘secondary’ explosive is mixed with zinc peroxide. Secondary explosives include nitrocellulose, pentaerythritol tetranitrate (PETN), as well as a variety of compounds, like trinitrobenzene, which provide powerful negative charge balance. These secondary explosives are relatively insensitive to stimuli such as physical impact, heat or charge. The explosive mixture would be comprised, in bulk, of the secondary explosive with a much smaller fraction of zinc peroxide, present to initiate the reaction.
Zinc peroxide | Pyrotechnics
Werner also described a second achiral hexol (a minor byproduct from the production of Fremy's salt) that he incorrectly identified as a linear tetramer. The second hexol is hexanuclear (contains six cobalt centres in each ion), not tetranuclear.
Hexol | The "second hexol"
"Am"-UO is produced by the thermal decomposition of uranyl peroxide tetrahydrate at temperatures between 150 and 500 °C, in either an air or nitrogen atmosphere. The resultant powder is tan orange in colour. Further heating results in the formation of alpha uranium trioxide (α-UO).
Amorphous uranium(VI) oxide | Production
Nitrite produced in the first step of autotrophic nitrification is oxidized to nitrate by nitrite oxidoreductase (NXR)(2). It is a membrane-associated iron-sulfur molybdoprotein, and is part of an electron transfer chain which channels electrons from nitrite to molecular oxygen. The molecular mechanism of oxidation nitrite is less described than oxidation ammonium. In new research (e.g. Woźnica A. et al., 2013) proposed new hypothetical model of NOB electron transport chain and NXR mechanism (Figure 2.). In contrast to earlier models the NXR acts on the outside of the plasma membrane, directly contributing to postulated by Spieck and coworkers mechanism of proton gradient generation.
Nitrifying bacteria | Second step nitrification - molecular mechanism
In form of a thin film ZnO has been demonstrated in miniaturised high frequency thin film resonators, sensors and filters.
Zinc oxide | Piezoelectricity
The acidity of aqueous ZnCl solutions relative to solutions of other Zn salts is due to the formation of the tetrahedral chloro aqua complexes where the reduction in coordination number from 6 to 4 further reduces the strength of the O–H bonds in the solvated water molecules. In alkali solution in the presence of OH ion various zinc hydroxychloride anions are present in solution, e.g. Zn(OH)Cl, Zn(OH), ZnOH, and Zn(OH)Cl·HO (simonkolleite) precipitates. When ammonia is bubbled through a solution of zinc chloride, the hydroxide does not precipitate, instead compounds containing complexed ammonia (ammines) are produced, Zn(NH)Cl·HO and on concentration ZnCl(NH).
Zinc chloride | Reactions
Ellingham diagrams are generated according to the second law of thermodynamics and are a graphical representation of the change in the Gibbs free energy with respect to changing temperature for the formation of oxides.
Metal oxide adhesion | Oxide stability
A common approach to preparing aluminium sulfacetate is by reaction of aluminium sulfate with lead(II) acetate. The relative amount of each reagent controls the composition of the resulting mixture. When the stoichiometric ratio of lead acetate to aluminium sulfate exceeds 3:1, the process is theoretically driven to completion and aluminium triacetate is the sole product. With less lead acetate, a mixture of aluminium triacetate and aluminium sulfacetate results that becomes increasingly rich in the latter as the reagent mole ratio approaches 2:1. This approach is used to form various mixtures for mordant applications: Basic aluminium sulfacetates can also be prepared, , with hydroxide anions replacing some acetate ions.
Aluminium sulfacetate | Preparation
Zinc oxide is an inorganic compound with the formula . ZnO is a white powder that is insoluble in water. It is used as an additive in numerous materials and products including cosmetics, food supplements, rubbers, plastics, ceramics, glass, cement, lubricants, paints, ointments, adhesives, sealants, pigments, foods, batteries, ferrites, fire retardants, and first-aid tapes. Although it occurs naturally as the mineral zincite, most zinc oxide is produced synthetically. ZnO is a wide-band gap semiconductor of the II-VI semiconductor group. The native doping of the semiconductor due to oxygen vacancies or zinc interstitials is n-type. Other favorable properties include good transparency, high electron mobility, wide band gap, and strong room-temperature luminescence.
Zinc oxide | Introduction
Acetic acid is an example of one possible byproduct from hot copper oxidation. It is used to convert alcohols directly into gasoline.
ZSM-5 | Uses
In other studies it was found to approximate to the gross formulas 3UO·NH·5HO, The asymmetric stretching frequency of the uranyl ion was found to decrease with increasing NH content. This decrease is continuous and no band splitting was observed, indicating that the ammonium uranate system is homogeneous and continuous. ADU is an intermediate in the production of uranium oxides to be used as nuclear fuel; it is converted directly into an oxide by heating. β-UO is produced at about 350 °C and UO is obtained at higher temperatures. When the alkali used is sodium hydroxide, so-called sodium diuranate, SDU, is produced.
Uranate | Properties and uses
The second step of the Birch reduction affording unconjugated cyclohexadienes also poses mechanistic questions. Thus as shown in the figure below there are three resonance structures B, C and D for the carbanion. Simple Hückel computations lead, as noted in the first entry of the table below, to equal electron densities at the three atoms 1, 3 and 5. However, in contrast to densities the Hückel computation is less naive about bond orders, and bonds 2–3 and 5–6 will be shortened as shown in the first entry of the table. With bond orders modifying simple exchange integrals in a Mulliken-Wheland-Mann computation it was shown that electron density at the central atom 1 become largest.
Birch reduction | Second step of the Birch reduction with regiochemistry giving unconjugated cyclohexadienes
Ammonium perchlorate (AP) is produced by reaction between ammonia and perchloric acid. This process is the main outlet for the industrial production of perchloric acid. The salt also can be produced by salt metathesis reaction of ammonium salts with sodium perchlorate. This process exploits the relatively low solubility of NHClO, which is about 10% of that for sodium perchlorate. AP crystallises as colorless rhombohedra.
Ammonium perchlorate | Production
Between 50% and 60% of ZnO use is in the rubber industry. Zinc oxide along with stearic acid is used in the vulcanization of rubber ZnO additive also protect rubber from fungi (see medical applications) and UV light.
Zinc oxide | Rubber manufacture
The authors discussed but dismissed the suggestion that the carboxylate function might bind to the catalytically functional zinc ion present at the active site. Later however this was found to be the case.
Discovery and development of ACE inhibitors | Development of first generation ACE inhibitors
Binary compounds of zinc are known for most of the metalloids and all the nonmetals except the noble gases. The oxide ZnO is a white powder that is nearly insoluble in neutral aqueous solutions, but is amphoteric, dissolving in both strong basic and acidic solutions. The other chalcogenides (ZnS, ZnSe, and ZnTe) have varied applications in electronics and optics. Pnictogenides (, , and ), the peroxide (), the hydride (), and the carbide () are also known. Of the four halides, has the most ionic character, while the others (, , and ) have relatively low melting points and are considered to have more covalent character.
Zinc | Zinc(II) compounds
Zinc sulfate is produced by treating virtually any zinc-containing material (metal, minerals, oxides) with sulfuric acid. Specific reactions include the reaction of the metal with aqueous sulfuric acid: Pharmaceutical-grade zinc sulfate is produced by treating high-purity zinc oxide with sulfuric acid: In aqueous solution, all forms of zinc sulfate behave identically. These aqueous solutions consist of the metal aquo complex [Zn(HO)] and SO ions. Barium sulfate forms when these solutions are treated with solutions of barium ions: With a reduction potential of -0.76, zinc(II) reduces only with difficulty.
Zinc sulfate | Production and reactivity
Measuring the speed of second sound in He-He mixtures can be used as a thermometer in the range 0.01-0.7 K. Oscillating superleak transducers (OST) use second sound to locate defects in superconducting accelerator cavities.
Second sound | Applications
2-Iodobenzoic acid can be synthesized "via" a Sandmeyer reaction consisting of the diazotization of anthranilic acid followed by a diazo replacement. First anthranilic acid is treated with nitrous acid in order to convert the amino group into the diazo group. The diazo group is ejected, yielding a carbocation which is then attacked by highly nucleophilic I anion. The nitrous acid is usually generated "in situ" from sodium nitrite.
2-Iodobenzoic acid | Synthesis
The reaction requires zinc ions as co-factors.
ELAC2 | Function
isopropanol (<0.5%). Therefore, in the continuous industrial process an aqueous sodium hydrogen sulfite solution is prepared in a first reactor by mixing a sodium hydroxide solution and sulfur dioxide. In a second reactor the sodium hydrogen sulfite solution is mixed with a slight excess of ethylene oxide to obtain sodium 2-hydroxyethyl sulfonate in almost quantitative yields at elevated temperature and pressure with a precise control of pH. The reaction has to take place under the exclusion of oxygen and under precise control of the stoichiometry of the reactants, the temperature, the pH and the throughput.
Sodium 2-hydroxyethyl sulfonate | Production
The reaction mechanism for this reaction is not known with great precision despite experimental evidence: A mechanism not inconsistent with these findings is depicted below: First, azoxybenzene undergoes protonation twice to afford a gitionic intermediate. The difficulty of protonating next to an already cationic nitrogen makes this second protonation step rate-determining. Water is eliminated to give the inferred symmetric intermediate, which is again gitionic and superelectrophilic. Water adds at the terminal position to give an intermediate that undergoes two successive deprotonation steps to give the 4-hydroxyazobenzene.
Wallach rearrangement | Reaction mechanism
The second stage is the oxidation of the carbon in the remaining sample in the form of carbon dioxide (CO) and other gases. Modern TOC analyzers perform this oxidation step by several processes:
Total organic carbon | Oxidation
The material produced was 35% CuO, 27% CuO, and 38% CuO. The process consists of the leaching of copper or its oxides with concentrated aqueous ammonia in a Soxhlet extractor. The reaction forms a deep blue complex of cupric ammonium that is converted to a residue of black oxide in the apparatus.
Paramelaconite | Synthesis
As the current travels around the circuit, when the electrons enter the cathode (carbon rod), they combine with manganese dioxide (MnO) and water (HO), which react with each other to produce manganese oxide (MnO) and negatively charged hydroxide ions. This is accompanied by a secondary acid-base reaction in which the hydroxide ions (OH) accept a proton (H) from the ammonium ions present in the ammonium chloride electrolyte to produce molecules of ammonia and water.
Leclanché cell | Chemistry
PBT2 is a safe-for-human-use Zinc ionophore and an experimental drug candidate. It is a second-generation 8-hydroxyquinoline analog intended to be a successor to clioquinol and a potential treatment of Alzheimer's disease and Huntington's disease.
PBT2 | Introduction
Evans:
Organozinc compound | Zinc acetylides