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*Sodium carbonate
*Sodium acetate
*Potassium cyanide
*Sodium sulfide
*Sodium bicarbonate
*Sodium hydroxide | 0 | Salts |
The colour of an ionic compound is often different from the colour of an aqueous solution containing the constituent ions, or the hydrated form of the same compound.
The anions in compounds with bonds with the most ionic character tend to be colorless (with an absorption band in the ultraviolet part of the spectrum). In compounds with less ionic character, their color deepens through yellow, orange, red, and black (as the absorption band shifts to longer wavelengths into the visible spectrum).
The absorption band of simple cations shifts toward a shorter wavelength when they are involved in more covalent interactions. This occurs during hydration of metal ions, so colorless anhydrous ionic compounds with an anion absorbing in the infrared can become colorful in solution.
Salts exist in many different colors, which arise either from their constituent anions, cations or solvates. For example:
* sodium chromate is made yellow by the chromate ion .
* potassium dichromate is made red-orange by the dichromate ion .
* cobalt(II) nitrate hexahydrate is made red by the chromophore of hydrated cobalt(II) .
* copper(II) sulfate pentahydrate is made blue by the hydrated copper(II) cation.
* potassium permanganate is made violet by the permanganate anion .
* nickel(II) chloride hexahydrate is made green by the hydrated nickel(II) chloride .
* sodium chloride NaCl and magnesium sulfate heptahydrate are colorless or white because the constituent cations and anions do not absorb light in the part of the spectrum that is visible to humans.
Some minerals are salts, some of which are soluble in water. Similarly, inorganic pigments tend not to be salts, because insolubility is required for fastness. Some organic dyes are salts, but they are virtually insoluble in water. | 0 | Salts |
Indium(III) selenide is a compound of indium and selenium. It has potential for use in photovoltaic devices and has been the subject of extensive research. The two most common phases, α and β, have a layered structure, while γ has a "defect wurtzite structure." In all, five polymorphs are known: α, β, γ, δ, κ. The α-β phase transition is accompanied by a change in electrical conductivity. The band gap of γ-InSe is approximately 1.9 eV. | 1 | Semiconductor Materials |
Note: Some of the following are also partly fresh and/or brackish water.
*Aral Sea
*Aralsor
*Aydar Lake
*Bakhtegan Lake
*Caspian Sea
*Chilika Lake
*Chott el Djerid
*Dabusun Lake
*Dead Sea
*Devil's Lake
*Don Juan Pond
*Garabogazköl
*Goose Lake
*Great Salt Lake
*Grevelingen
*Laguna Colorada
*Laguna Verde
*Lake Abert
*Lake Alakol
*Lake Assal
*Lake Balkhash
*Lake Barlee
*Lake Baskunchak
*Lake Bumbunga
*Lake Enriquillo
*Lake Elton
*Lake Eyre
*Lake Gairdner
*Lake Hillier
*Lake Karum
*Lake Mackay
*Lake Natron
*Lake Paliastomi
*Lake Pontchartrain
*Lake Texoma
*Lake Torrens
*Lake Tuz
*Lake Tyrrell
*Lake Urmia
*Lake Van
*Lake Vanda
*Larnaca Salt Lake
*Little Manitou Lake
*Lough Hyne
*Lonar Lake
*Maharloo Lake
*Mar Chiquita Lake
*Mono Lake
*Nam Lake
*Pangong Lake
*Pulicat Lake
*Qarhan Playa
*Redberry Lake
*Salton Sea
*Sambhar Salt Lake
*Sarygamysh Lake
*Sawa Lake
*Siling Lake
*South Hulsan Lake
*Sutton Salt Lake
*Uvs Lake | 0 | Salts |
After about 1820, New York replaced New England as the most important source; by 1840 the center was in Ohio. Potash production was always a by-product industry, following from the need to clear land for agriculture. | 0 | Salts |
The early development of this type of complex takes place around the turn of the 19th century. In 1886 Janovski observed an intense violet color when he mixed meta-dinitrobenzene with an alcoholic solution of alkali. In 1895 Cornelis Adriaan Lobry van Troostenburg de Bruyn investigated a red substance formed in the reaction of trinitrobenzene with potassium hydroxide in methanol. In 1900 Jackson and Gazzolo reacted trinitroanisole with sodium methoxide and proposed a quinoid structure for the reaction product.
In 1902 Jakob Meisenheimer observed that by acidifying their reaction product, the starting material was recovered.
With three electron withdrawing groups, the negative charge in the complex is located at one of the nitro groups according to the quinoid model. When less electron poor arenes this charge is delocalized over the entire ring (structure to the right in scheme 1).
In one study a Meisenheimer arene (4,6-dinitrobenzofuroxan) was allowed to react with a strongly electron-releasing arene (1,3,5-tris(N-pyrrolidinyl)benzene) forming a zwitterionic Meisenheimer–Wheland complex. The Wheland intermediate is the name typically given to the cationic reactive intermediate formed in electrophilic aromatic substitution, and can be considered an oppositely charged analog of the negatively charged Meisenheimer complex formed in nucleophilic aromatic substitution. Hence, the simultaneous occurrence of the Wheland and Meisenheimer intermediates in the single zwitterionic complex shown below lead to its description as a Meisenheimer–Wheland complex.
The structure of this complex was confirmed by NMR spectroscopy. | 0 | Salts |
Carbides can be generally classified by the chemical bonds type as follows:
# salt-like (ionic),
# covalent compounds,
# interstitial compounds, and
# "intermediate" transition metal carbides.
Examples include calcium carbide (CaC), silicon carbide (SiC), tungsten carbide (WC; often called, simply, carbide when referring to machine tooling), and cementite (FeC), each used in key industrial applications. The naming of ionic carbides is not systematic. | 0 | Salts |
Molecular wires can be incorporated into polymers, enhancing their mechanical and/or conducting properties. The enhancement of these properties relies on uniform dispersion of the wires into the host polymer. MoSI wires have been made in such composites, relying on their superior solubility within the polymer host compared to other nanowires or nanotubes. Bundles of wires can be used to enhance tribological properties of polymers, with applications in actuators and potentiometers. It has been recently proposed that twisted nanowires could work as electromechanical nanodevices (or torsion nanobalances) to measure forces and torques at nanoscale with great precision. | 1 | Semiconductor Materials |
MoS is naturally found as either molybdenite, a crystalline mineral, or jordisite, a rare low temperature form of molybdenite. Molybdenite ore is processed by flotation to give relatively pure . The main contaminant is carbon. also arises by thermal treatment of virtually all molybdenum compounds with hydrogen sulfide or elemental sulfur and can be produced by metathesis reactions from molybdenum pentachloride. | 1 | Semiconductor Materials |
Platinum silicide, also known as platinum monosilicide, is the inorganic compound with the formula PtSi. It is a semiconductor that turns into a superconductor when cooled to 0.8 K. | 1 | Semiconductor Materials |
Copper(II) chloride is used in pyrotechnics as a blue/green coloring agent. In a flame test, copper chlorides, like all copper compounds, emit green-blue light.
In humidity indicator cards (HICs), cobalt-free brown to azure (copper(II) chloride base) HICs can be found on the market. In 1998, the European Community classified items containing cobalt(II) chloride of 0.01 to 1% w/w as T (Toxic), with the corresponding R phrase of R49 (may cause cancer if inhaled). Consequently, new cobalt-free humidity indicator cards containing copper have been developed.
Copper(II) chloride is used as a mordant in the textile industry, petroleum sweetener, wood preservative, and water cleaner. | 1 | Semiconductor Materials |
Iron-pyrite FeS represents the prototype compound of the crystallographic pyrite structure. The structure is cubic and was among the first crystal structures solved by X-ray diffraction. It belongs to the crystallographic space group Pa and is denoted by the Strukturbericht notation C2. Under thermodynamic standard conditions the lattice constant of stoichiometric iron pyrite FeS amounts to . The unit cell is composed of a Fe face-centered cubic sublattice into which the ions are embedded. (Note though that the iron atoms in the faces are not equivalent by translation alone to the iron atoms at the corners.) The pyrite structure is also seen in other MX compounds of transition metals M and chalcogens X = O, S, Se and Te. Certain dipnictides with X standing for P, As and Sb etc. are also known to adopt the pyrite structure.
The Fe atoms are bonded to six S atoms, giving a distorted octahedron. The material is a semiconductor. The Fe ions is usually considered to be low spin divalent state (as shown by Mössbauer spectroscopy as well as XPS). The material as a whole behaves as a Van Vleck paramagnet, despite its low-spin divalency.
The sulfur centers occur in pairs, described as S.. This material features ferric ions and isolated sulfide (S) centers.
The S atoms are tetrahedral, being bonded to three Fe centers and one other S atom. The site symmetry at Fe and S positions is accounted for by point symmetry groups C and C, respectively. The missing center of inversion at S lattice sites has important consequences for the crystallographic and physical properties of iron pyrite. These consequences derive from the crystal electric field active at the sulfur lattice site, which causes a polarization of S ions in the pyrite lattice. The polarisation can be calculated on the basis of higher-order Madelung constants and has to be included in the calculation of the lattice energy by using a generalised Born–Haber cycle. This reflects the fact that the covalent bond in the sulfur pair is inadequately accounted for by a strictly ionic treatment.
Arsenopyrite has a related structure with heteroatomic As–S pairs rather than S-S pairs. Marcasite also possesses homoatomic anion pairs, but the arrangement of the metal and diatomic anions differ from that of pyrite. Despite its name, chalcopyrite () does not contain dianion pairs, but single S sulfide anions. | 1 | Semiconductor Materials |
Molybdenite occurs in high temperature hydrothermal ore deposits.
Its associated minerals include pyrite, chalcopyrite, quartz, anhydrite, fluorite, and scheelite. Important deposits include the disseminated porphyry molybdenum deposits at Questa, New Mexico and the Henderson and Climax mines in Colorado. Molybdenite also occurs in porphyry copper deposits of Arizona, Utah, and Mexico.
The element rhenium is always present in molybdenite as a substitute for molybdenum, usually in the parts per million (ppm ) range, but often up to 1–2%. High rhenium content results in a structural variety detectable by X-ray diffraction techniques. Molybdenite ores are essentially the only source for rhenium. The presence of the radioactive isotope rhenium-187 and its daughter isotope osmium-187 provides a useful geochronologic dating technique. | 1 | Semiconductor Materials |
Pyrite enjoyed brief popularity in the 16th and 17th centuries as a source of ignition in early firearms, most notably the wheellock, where a sample of pyrite was placed against a circular file to strike the sparks needed to fire the gun.
Pyrite is used with flintstone and a form of tinder made of stringybark by the Kaurna people of South Australia, as a traditional method of starting fires.
Pyrite has been used since classical times to manufacture copperas (ferrous sulfate). Iron pyrite was heaped up and allowed to weather (an example of an early form of heap leaching). The acidic runoff from the heap was then boiled with iron to produce iron sulfate. In the 15th century, new methods of such leaching began to replace the burning of sulfur as a source of sulfuric acid. By the 19th century, it had become the dominant method.
Pyrite remains in commercial use for the production of sulfur dioxide, for use in such applications as the paper industry, and in the manufacture of sulfuric acid. Thermal decomposition of pyrite into FeS (iron(II) sulfide) and elemental sulfur starts at ; at around , p</sub> is about .
A newer commercial use for pyrite is as the cathode material in Energizer brand non-rechargeable lithium metal batteries.
Pyrite is a semiconductor material with a band gap of 0.95 eV. Pure pyrite is naturally n-type, in both crystal and thin-film forms, potentially due to sulfur vacancies in the pyrite crystal structure acting as n-dopants.
During the early years of the 20th century, pyrite was used as a mineral detector in radio receivers, and is still used by crystal radio hobbyists. Until the vacuum tube matured, the crystal detector was the most sensitive and dependable detector available—with considerable variation between mineral types and even individual samples within a particular type of mineral. Pyrite detectors occupied a midway point between galena detectors and the more mechanically complicated perikon mineral pairs. Pyrite detectors can be as sensitive as a modern 1N34A germanium diode detector.
Pyrite has been proposed as an abundant, non-toxic, inexpensive material in low-cost photovoltaic solar panels. Synthetic iron sulfide was used with copper sulfide to create the photovoltaic material. More recent efforts are working toward thin-film solar cells made entirely of pyrite.
Pyrite is used to make marcasite jewelry. Marcasite jewelry, made from small faceted pieces of pyrite, often set in silver, was known since ancient times and was popular in the Victorian era. At the time when the term became common in jewelry making, "marcasite" referred to all iron sulfides including pyrite, and not to the orthorhombic FeS mineral marcasite which is lighter in color, brittle and chemically unstable, and thus not suitable for jewelry making. Marcasite jewelry does not actually contain the mineral marcasite. The specimens of pyrite, when it appears as good quality crystals, are used in decoration. They are also very popular in mineral collecting. Among the sites that provide the best specimens are Soria and La Rioja provinces (Spain).
In value terms, China ($47 million) constitutes the largest market for imported unroasted iron pyrites worldwide, making up 65% of global imports. China is also the fastest growing in terms of the unroasted iron pyrites imports, with a CAGR of +27.8% from 2007 to 2016. | 1 | Semiconductor Materials |
Molybdenite is extremely soft with a metallic luster, and is superficially almost identical to graphite, to the point where it is not possible to positively distinguish between the two minerals without scientific equipment. It marks paper in much the same way as graphite. Its distinguishing feature from graphite is its higher specific gravity, as well as its tendency to occur in a matrix. | 1 | Semiconductor Materials |
Salts can elicit all five basic tastes, e.g., salty (sodium chloride), sweet (lead diacetate, which will cause lead poisoning if ingested), sour (potassium bitartrate), bitter (magnesium sulfate), and umami or savory (monosodium glutamate).
Salts of strong acids and strong bases ("strong salts") are non-volatile and often odorless, whereas salts of either weak acids or weak bases ("weak salts") may smell like the conjugate acid (e.g., acetates like acetic acid (vinegar) and cyanides like hydrogen cyanide (almonds)) or the conjugate base (e.g., ammonium salts like ammonia) of the component ions. That slow, partial decomposition is usually accelerated by the presence of water, since hydrolysis is the other half of the reversible reaction equation of formation of weak salts. | 0 | Salts |
Normal saline (NSS, NS or N/S) is the commonly used phrase for a solution of 0.90% w/v of NaCl, 308 mOsm/L or 9.0 g per liter. Less commonly, this solution is referred to as physiological saline or isotonic saline (because it is approximately isotonic to blood serum, which makes it a physiologically normal solution). Although neither of those names is technically accurate because normal saline is not exactly like blood serum, they convey the practical effect usually seen: good fluid balance with minimal hypotonicity or hypertonicity. NS is used frequently in intravenous drips (IVs) for people who cannot take fluids orally and have developed or are in danger of developing dehydration or hypovolemia. NS is also used for aseptic purpose. NS is typically the first fluid used when hypovolemia is severe enough to threaten the adequacy of blood circulation, and has long been believed to be the safest fluid to give quickly in large volumes. However, it is now known that rapid infusion of NS can cause metabolic acidosis.
The solution is 9 grams of sodium chloride (NaCl) dissolved in water, to a total volume of 1000 ml (weight per unit volume). The mass of 1 millilitre of normal saline is 1.0046 grams at 22 °C. The molecular weight of sodium chloride is approximately 58.4 grams per mole, so 58.4 grams of sodium chloride equals 1 mole. Since normal saline contains 9 grams of NaCl, the concentration is 9 grams per litre divided by 58.4 grams per mole, or 0.154 mole per litre. Since NaCl dissociates into two ions – sodium and chloride – 1 molar NaCl is 2 osmolar. Thus, NS contains 154 mEq/L of Na and the same amount of Cl. This points to an osmolarity of 154 + 154 = 308, which is higher (i.e. more solute per litre) than that of blood (approximately 285). However, if the osmotic coefficient (a correction for non-ideal solutions) is taken into account, then the saline solution is much closer to isotonic. The osmotic coefficient of NaCl is about 0.93, which yields an osmolarity of 0.154 × 1000 × 2 × 0.93 = 286.44. Therefore, the osmolarity of normal saline is a close approximation to the osmolarity of blood. | 0 | Salts |
Ionic compounds containing hydrogen ions (H) are classified as acids, and those containing electropositive cations and basic anions ions hydroxide (OH) or oxide (O) are classified as bases. Other ionic compounds are known as salts and can be formed by acid–base reactions. If the compound is the result of a reaction between a strong acid and a weak base, the result is an acidic salt. If it is the result of a reaction between a strong base and a weak acid, the result is a basic salt. If it is the result of a reaction between a strong acid and a strong base, the result is a neutral salt. Weak acids reacted with weak bases can produce ionic compounds with both the conjugate base ion and conjugate acid ion, such as ammonium acetate.
Some ions are classed as amphoteric, being able to react with either an acid or a base. This is also true of some compounds with ionic character, typically oxides or hydroxides of less-electropositive metals (so the compound also has significant covalent character), such as zinc oxide, aluminium hydroxide, aluminium oxide and lead(II) oxide. | 0 | Salts |
The production of toilet soaps usually entails saponification of triglycerides, which are vegetable or animal oils and fats. An alkaline solution (often lye or sodium hydroxide) induces saponification whereby the triglyceride fats first hydrolyze into salts of fatty acids. Glycerol (glycerin) is liberated. The glycerin can remain in the soap product as a softening agent, although it is sometimes separated.
The type of alkali metal used determines the kind of soap product. Sodium soaps, prepared from sodium hydroxide, are firm, whereas potassium soaps, derived from potassium hydroxide, are softer or often liquid. Historically, potassium hydroxide was extracted from the ashes of bracken or other plants. Lithium soaps also tend to be hard. These are used exclusively in greases.
For making toilet soaps, triglycerides (oils and fats) are derived from coconut, olive, or palm oils, as well as tallow. Triglyceride is the chemical name for the triesters of fatty acids and glycerin. Tallow, i.e., rendered fat, is the most available triglyceride from animals. Each species offers quite different fatty acid content, resulting in soaps of distinct feel. The seed oils give softer but milder soaps. Soap made from pure olive oil, sometimes called Castile soap or Marseille soap, is reputed for its particular mildness. The term "Castile" is also sometimes applied to soaps from a mixture of oils with a high percentage of olive oil. | 0 | Salts |
Potash (especially potassium carbonate) has been used in bleaching textiles, making glass, ceramic, and making soap, since the Bronze Age. Potash was principally obtained by leaching the ashes of land plants. | 0 | Salts |
By complexing metal ions into the polymer matrix, the strength and toughness of the ionomer system is increased. Some applications where ionomers were used to increase the toughness of the overall system include coatings, adhesives, impact modification, and thermoplastics, one of the most known examples being the use of Surlyn in the outer layer of golf balls. The ionomer coating improves the toughness, aerodynamics, and durability of the golf balls, increasing their lifetime. Ionomers can also be blended with resins to increase the cohesive strength without diminishing the overall tackiness of the resin, creating pressure sensitive adhesives for a variety of applications, including water or solvent-based adhesives. Ionomers using poly(ethylene-methacrylic acid) chains can also be used in film packaging due to their transparency, toughness, flexibility, resistance to staining, high gas permeability, and low sealing temperature. These qualities also translate to a high demand for using the ionomers in food-packing materials.
With the addition of the ion to a certain percentage of the polymer chain, the viscosity of the ionomer increases. This behavior can make ionomers a good viscosification material for drilling fluid applications where the system is under a low shear rate. Using the ionomer to increase the viscosity of the system helps prevent shear thinning behaviors within the drilling fluid, especially at higher temperatures of operation.
Another application includes the ability of an ionomer to increase the compatibility of polymer blends. This phenomenon is driven by thermodynamics and is achieved through the introduction of specific interactions between functional groups that are increasingly favorable in the presence of a metal ion. The miscibility can be driven not only by the increasingly favorable reaction between functional groups on two different polymers but also by having a strong repulsive interaction between the neutral and ionic species present within an ionomer, which can drive one of these species to be more miscible with the species of the other polymer within the blend. Some ionomers have been used for shape memory applications, meaning the material has a fixed shape that can be reformed using external stresses above a critical temperature and cooled, then regains the original shape when brought above the critical temperature and allowed to cool under no external stresses. Ionomers can form both chemical and physical crosslinks that can be modified easily at moderate processing temperatures, are less dense than shape memory alloys, and have a higher chance of being biocompatible for biomedical devices.
Some more recent applications for ionomers include being used as ion-selective membranes in a variety of electrical and energy applications. Examples include the cation exchange membrane for fuel cells, which allow only protons or specific ions to cross the membrane, a polymer electrolyte membrane (PEM) water electrolyzer to optimize the uniform coating of the catalyst on membrane surfaces, a redox flow battery separator, electrodialysis, where ions are transported between solutions using the ionomer membrane, and electrochemical hydrogen compressors to increase the strength of the membrane against the pressure differentials that can occur within the compressor. | 0 | Salts |
Molybdenum disulfide is stable in air and attacked only by aggressive reagents. It reacts with oxygen upon heating forming molybdenum trioxide:
Chlorine attacks molybdenum disulfide at elevated temperatures to form molybdenum pentachloride: | 1 | Semiconductor Materials |
In chemistry, a plumbate often refers to compounds that can be viewed as derivatives of the hypothetical anion. | 0 | Salts |
Graphitic carbon nitride (g-CN) is a family of carbon nitride compounds with a general formula near to CN (albeit typically with non-zero amounts of hydrogen) and two major substructures based on heptazine and poly(triazine imide) units which, depending on reaction conditions, exhibit different degrees of condensation, properties and reactivities. | 1 | Semiconductor Materials |
Molybdenum disulfide (or moly) is an inorganic compound composed of molybdenum and sulfur. Its chemical formula is .
The compound is classified as a transition metal dichalcogenide. It is a silvery black solid that occurs as the mineral molybdenite, the principal ore for molybdenum. is relatively unreactive. It is unaffected by dilute acids and oxygen. In appearance and feel, molybdenum disulfide is similar to graphite. It is widely used as a dry lubricant because of its low friction and robustness. Bulk is a diamagnetic, indirect bandgap semiconductor similar to silicon, with a bandgap of 1.23 eV. | 1 | Semiconductor Materials |
Many metals such as the alkali metals react directly with the electronegative halogens gases to salts.
Salts form upon evaporation of their solutions. Once the solution is supersaturated and the solid compound nucleates. This process occurs widely in nature and is the means of formation of the evaporite minerals.
Insoluble ionic compounds can be precipitated by mixing two solutions, one with the cation and one with the anion in it. Because all solutions are electrically neutral, the two solutions mixed must also contain counterions of the opposite charges. To ensure that these do not contaminate the precipitated ionic compound, it is important to ensure they do not also precipitate. If the two solutions have hydrogen ions and hydroxide ions as the counterions, they will react with one another in what is called an acid–base reaction or a neutralization reaction to form water. Alternately the counterions can be chosen to ensure that even when combined into a single solution they will remain soluble as spectator ions.
If the solvent is water in either the evaporation or precipitation method of formation, in many cases the ionic crystal formed also includes water of crystallization, so the product is known as a hydrate, and can have very different chemical properties compared to the anhydrous material.
Molten salts will solidify on cooling to below their freezing point. This is sometimes used for the solid-state synthesis of complex ionic compounds from solid reactants, which are first melted together. In other cases, the solid reactants do not need to be melted, but instead can react through a solid-state reaction route. In this method, the reactants are repeatedly finely ground into a paste and then heated to a temperature where the ions in neighboring reactants can diffuse together during the time the reactant mixture remains in the oven. Other synthetic routes use a solid precursor with the correct stoichiometric ratio of non-volatile ions, which is heated to drive off other species.
In some reactions between highly reactive metals (usually from Group 1 or Group 2) and highly electronegative halogen gases, or water, the atoms can be ionized by electron transfer, a process thermodynamically understood using the Born–Haber cycle.
Salts are formed by salt-forming reactions
*A base and an acid, e.g., NH + HCl → NHCl
*A metal and an acid, e.g., Mg + HSO → MgSO + H
*A metal and a non-metal, e.g., Ca + Cl → CaCl
*A base and an acid anhydride, e.g., 2 NaOH + ClO → 2 NaClO + HO
*An acid and a base anhydride, e.g., 2 HNO + NaO → 2 NaNO + HO
*In the salt metathesis reaction where two different salts are mixed in water, their ions recombine, and the new salt is insoluble and precipitates. For example:
*: Pb(NO) + NaSO → PbSO↓ + 2 NaNO | 0 | Salts |
The organized and uniform collection of tax revenue on salt in British India began under the British Raj. Both before and after that, various native rulers of the Indian Princely states (outside British India proper) collected such revenue in accordance with their own revenue and administrative requirements and resources. In 1856, the government appointed the young William Chichele Plowden, Secretary of the Board of Revenue of the North West Provinces, to report on the establishment of a uniform system of revenue realisation from salt within the British Provinces, and he recommended the extension of the excise system, the reduction of duty, and the introduction of a system of licensing as the measures to achieve this goal.
In 1876, separate departments under a Salt Commissioner were set up, and these operated at the level of each British Province and Presidency. It was with the passing of the Government of India Act 1935, that within British India (which then included much of present-day Pakistan) salt came under the exclusive control of the central government, with the Government of India taking over the task of collecting salt revenue and transferring it from the provincial salt agencies to the Central Excise and Revenue Department. In 1944, the Government of India passed the Central Excises and Salt Act which unified and amended all laws dealing with duties on excise and salt.
The Salt Department was originally a part of the Central Board of Revenue under the Ministry of Finance, but since a reorganisation of the ministries of India in 1957 it has come under the authority of the Ministry of Commerce and Industry.
According to the Union List of subjects under the Seventh Schedule of the Indian Constitution, the "manufacture, supply and distribution of salt by Union agencies; regulation and control of manufacture, supply and distribution of salt by other agencies", is the responsibility of the Government of India. The posts of Salt Controller, Deputy Salt Controller and Assistant Salt Controller were re-categorized as Salt Commissioner, Deputy Salt Commissioner and Assistant Salt Commissioner in 1952 and the Indian Salt Services were created in 1954 for the realisation of the entry under the Union List. The Salt Service has both Group A and Group B wings. | 0 | Salts |
Coral calcium is a salt of calcium derived from fossilized coral reefs (primarily from limestone and coastal deposits). It has been promoted as an alternative, but unsubstantiated, treatment or cure for a number of health conditions. | 0 | Salts |
Xanthate salts of alkali metals are produced by the treatment of an alcohol, alkali, and carbon disulfide. The process is called xanthation. In chemical terminology, the alkali reacts with the alcohol to produce an alkoxide, which is the nucleophile that adds to the electrophilic carbon atom in CS. Often the alkoxide is generated in situ by treating the alcohol with sodium hydroxide or potassium hydroxide:
:ROH + CS + KOH → ROCSK + HO
For example, sodium ethoxide gives sodium ethyl xanthate. Many alcohols can be used in this reaction. Technical grade xanthate salts are usually of 90–95% purity. Impurities include alkali metal sulfides, sulfates, trithiocarbonates, thiosulfates, sulfites, or carbonates as well as residual raw material such as alcohol and alkali hydroxide. These salts are available commercially as powder, granules, flakes, sticks, and solutions are available.
Some commercially or otherwise useful xanthate salts include:
* sodium ethyl xanthate CHCHOCSNa
* potassium ethyl xanthate, CHCHOCSK
* potassium isopropyl xanthate, (CH)CHOCSK
* sodium isobutyl xanthate, (CH)CHCHOCSNa
* potassium amyl xanthate, CH(CH)OCSK
The OCS core of xanthate salts, like that of the carbonates and the esters has trigonal planar molecular geometry. The central carbon atom is sp-hybridized. | 0 | Salts |
Potash ( ) includes various mined and manufactured salts that contain potassium in water-soluble form. The name derives from pot ash, plant ashes or wood ash soaked in water in a pot, the primary means of manufacturing potash before the Industrial Era. The word potassium is derived from potash.
Potash is produced worldwide in amounts exceeding 71.9 million tonnes (~45.4 million tonnes KO equivalent) per year as of 2021, with Canada being the largest producer, mostly for use in fertilizer. Various kinds of fertilizer-potash constitute the single greatest industrial use of the element potassium in the world. Potassium was first derived in 1807 by electrolysis of caustic potash (potassium hydroxide). | 0 | Salts |
Akin to the preparation of most xanthates, sodium ethyl xanthate can be prepared by treating sodium ethoxide with carbon disulfide: | 0 | Salts |
In chemistry, perxenates are salts of the yellow xenon-containing anion . This anion has octahedral molecular geometry, as determined by Raman spectroscopy, having O–Xe–O bond angles varying between 87° and 93°. The Xe–O bond length was determined by X-ray crystallography to be 1.875 Å. | 0 | Salts |
Percobaltates are chemical compounds where the oxidation state of cobalt is +5. This is the highest established oxidation state of cobalt. The simplest of these are bi-metallic Group 1 oxides such as sodium percobaltate (NaCoO); which may be produced by the reaction of cobalt(II,III) oxide and sodium oxide, using oxygen as the oxidant:
: 4 CoO + 18 NaO + 7 O → 12 NaCoO
The potassium salt can be synthesized similarly; its magnetic moment has indicated the existence of cobalt(V). No crystallographic analysis has been reported for either material. Percobaltates can be stabilized by use of oxides or fluorides.
A number of organometallic Co(V) complexes have also been reported. | 0 | Salts |
In materials and electric battery research, cobalt oxide nanoparticles usually refers to particles of cobalt(II,III) oxide of nanometer size, with various shapes and crystal structures.
Cobalt oxide nanoparticles have potential applications in lithium-ion batteries and electronic gas sensors. | 1 | Semiconductor Materials |
Tin(IV) oxide crystallises with the rutile structure. As such the tin atoms are six coordinate and the oxygen atoms three coordinate. SnO is usually regarded as an oxygen-deficient n-type semiconductor.
Hydrous forms of SnO have been described as stannic acid. Such materials appear to be hydrated particles of SnO where the composition reflects the particle size. | 1 | Semiconductor Materials |
Iron(II) selenide refers to a number of inorganic compounds of ferrous iron and selenide (Se). The phase diagram of the system Fe–Se reveals the existence of several non-stoichiometric phases between ~49 at. % Se and ~53 at. % Fe, and temperatures up to ~450 °C. The low temperature stable phases are the tetragonal PbO-structure (P4/nmm) β-FeSe and α-FeSe. The high temperature phase is the hexagonal, NiAs structure (P6/mmc) δ-FeSe. Iron(II) selenide occurs naturally as the NiAs-structure mineral achavalite.
More selenium rich iron selenide phases are the γ phases (γ and γˈ), assigned the FeSe stoichiometry, and FeSe, which occurs as the marcasite-structure natural mineral ferroselite, or the rare pyrite-structure mineral dzharkenite.
It is used in electrical semiconductors. | 1 | Semiconductor Materials |
When copper(II) chloride solutions are treated with a base, a precipitation of copper(II) hydroxide occurs:
Partial hydrolysis gives dicopper chloride trihydroxide, , a popular fungicide. When an aqueous solution of copper(II) chloride is left in the air and isn't stabilized by a small amount of acid, it is prone to undergo slight hydrolysis. | 1 | Semiconductor Materials |
Perxenates are synthesized by the disproportionation of xenon trioxide when dissolved in strong alkali:
:2 XeO () + 4 OH () → Xe () + () + O () + 2 HO ()
When Ba(OH) is used as the alkali, barium perxenate can be crystallized from the resulting solution. | 0 | Salts |
Lead(II) iodide (or lead iodide) is a chemical compound with the formula . At room temperature, it is a bright yellow odorless crystalline solid, that becomes orange and red when heated. It was formerly called plumbous iodide.
The compound currently has a few specialized applications, such as the manufacture of solar cells, X-rays and gamma-ray detectors. Its preparation is an entertaining and popular demonstration in chemistry education, to teach topics such as precipitation reactions and stoichiometry. It is decomposed by light at temperatures above , and this effect has been used in a patented photographic process.
Lead iodide was formerly employed as a yellow pigment in some paints, with the name iodide yellow. However, that use has been largely discontinued due to its toxicity and poor stability. | 1 | Semiconductor Materials |
Bittern can be used instead of aluminum-based coagulants in the treatment of wastewater produced during the fabric-dyeing process. The wastewater pH is basic, which is favorable for the use of bittern. After the addition of bittern, precipitated magnesium hydroxide works as the coagulant to collect dye, solids, organic matter, and heavy metals from the wastewater before settling out of solution. The sludge produced from this wastewater treatment is also easier to dispose of than sludge produced by aluminum-based coagulants because there are less restrictions surrounding the disposal of magnesium, and it may be possible to recycle the sludge as fertilizer.
Bittern can also be used as a source of magnesium ions (Mg) for the precipitation of struvite, a useful fertilizer, from wastewater containing nitrogen and phosphorus. One source of useful wastewater is landfill leachate. Bittern is just as good as other sources of magnesium ions at removing phosphorus from wastewater streams, but it lags behind other magnesium ion sources in terms of the removal of ammonia (a nitrogen compound). | 0 | Salts |
Sodium ethyl xanthate is a pale yellow powder. Its aqueous solutions are stable at high pH if not heated. It rapidly hydrolyses at pH less than 9 at 25 °C. It is the conjugate base of the ethyl xanthic acid, a strong acid with pK of 1.6 and pK estimated as 12.4 for the conjugate base. Sodium ethyl xanthate easily adsorbs on the surface of many sulfide minerals, a key step in froth flotation.
Xanthates are susceptible to hydrolysis and oxidation at low pH:
Oxidation gives diethyl dixanthogen disulfide: | 0 | Salts |
As in graphene, the layered structures of and other transition metal dichalcogenides exhibit electronic and optical properties that can differ from those in bulk. Bulk has an indirect band gap of 1.2 eV, while monolayers have a direct 1.8 eV electronic bandgap, supporting switchable transistors and photodetectors.
nanoflakes can be used for solution-processed fabrication of layered memristive and memcapacitive devices through engineering a / heterostructure sandwiched between silver electrodes. -based memristors are mechanically flexible, optically transparent and can be produced at low cost.
The sensitivity of a graphene field-effect transistor (FET) biosensor is fundamentally restricted by the zero band gap of graphene, which results in increased leakage and reduced sensitivity. In digital electronics, transistors control current flow throughout an integrated circuit and allow for amplification and switching. In biosensing, the physical gate is removed and the binding between embedded receptor molecules and the charged target biomolecules to which they are exposed modulates the current.
MoS has been investigated as a component of flexible circuits.
In 2017, a 115-transistor, 1-bit microprocessor implementation was fabricated using two-dimensional .
MoS has been used to create 2D 2-terminal memristors and 3-terminal memtransistors. | 1 | Semiconductor Materials |
Uranium oxide (urania) was used to color glass and ceramics prior to World War II, and until the applications of radioactivity were discovered this was its main use. In 1958 the military in both the US and Europe allowed its commercial use again as depleted uranium, and its use began again on a more limited scale. Urania-based ceramic glazes are dark green or black when fired in a reduction or when UO is used; more commonly it is used in oxidation to produce bright yellow, orange and red glazes. Orange-colored Fiestaware is a well-known example of a product with a urania-colored glaze. Uranium glass is pale green to yellow and often has strong fluorescent properties. Urania has also been used in formulations of enamel and porcelain. It is possible to determine with a Geiger counter if a glaze or glass produced before 1958 contains urania. | 1 | Semiconductor Materials |
Potassium is the third major plant and crop nutrient after nitrogen and phosphorus. It has been used since antiquity as a soil fertilizer (about 90% of current use). Elemental potassium does not occur in nature because it reacts violently with water. As part of various compounds, potassium makes up about 2.6% of the Earths crust by mass and is the seventh most abundant element, similar in abundance to sodium at approximately 1.8% of the crust. Potash is important for agriculture because it improves water retention, yield, nutrient value, taste, color, texture and disease resistance of food crops. It has wide application to fruit and vegetables, rice, wheat and other grains, sugar, corn, soybeans, palm oil and cotton, all of which benefit from the nutrients quality-enhancing properties.
Demand for food and animal feed has been on the rise since 2000. The United States Department of Agriculture's Economic Research Service (ERS) attributes the trend to average annual population increases of 75 million people around the world. Geographically, economic growth in Asia and Latin America greatly contributed to the increased use of potash-based fertilizer. Rising incomes in developing countries also were a factor in the growing potash and fertilizer use. With more money in the household budget, consumers added more meat and dairy products to their diets. This shift in eating patterns required more acres to be planted, more fertilizer to be applied and more animals to be fed—all requiring more potash.
After years of trending upward, fertilizer use slowed in 2008. The worldwide economic downturn is the primary reason for the declining fertilizer use, dropping prices, and mounting inventories.
The world's largest consumers of potash are China, the United States, Brazil, and India. Brazil imports 90% of the potash it needs. Potash consumption for fertilizers is expected to increase to about 37.8 million tonnes by 2022.
Potash imports and exports are often reported in KO equivalent, although fertilizer never contains potassium oxide, per se, because potassium oxide is caustic and hygroscopic. | 0 | Salts |
Brine is used as a secondary fluid in large refrigeration installations for the transport of thermal energy. Most commonly used brines are based on inexpensive calcium chloride and sodium chloride. It is used because the addition of salt to water lowers the freezing temperature of the solution and the heat transport efficiency can be greatly enhanced for the comparatively low cost of the material. The lowest freezing point obtainable for NaCl brine is at the concentration of 23.3% NaCl by weight. This is called the eutectic point.
Because of their corrosive properties salt-based brines have been replaced by organic liquids such as ethylene glycol.
Sodium chloride brine spray is used on some fishing vessels to freeze fish. The brine temperature is generally . Air blast freezing temperatures are or lower. Given the higher temperature of brine, the system efficiency over air blast freezing can be higher. High-value fish usually are frozen at much lower temperatures, below the practical temperature limit for brine. | 0 | Salts |
Salts are a natural component in soils and water.
The ions responsible for salination are: Na, K, Ca, Mg and Cl.<br/>
Over long periods of time, as soil minerals weather and release salts, these salts are flushed or leached out of the soil by drainage water in areas with sufficient precipitation. In addition to mineral weathering, salts are also deposited via dust and precipitation. Salts may accumulate in dry regions, leading to naturally saline soils. This is the case, for example, in large parts of Australia.
Human practices can increase the salinity of soils by the addition of salts in irrigation water. Proper irrigation management can prevent salt accumulation by providing adequate drainage water to leach added salts from the soil. Disrupting drainage patterns that provide leaching can also result in salt accumulations. An example of this occurred in Egypt in 1970 when the Aswan High Dam was built. The change in the level of ground water before the construction had enabled soil erosion, which led to high concentration of salts in the water table. After the construction, the continuous high level of the water table led to the salination of arable land. | 0 | Salts |
It is best known as the material for CIGS solar cells a thin-film technology used in the photovoltaic industry. In this role, CIGS has the advantage of being able to be deposited on flexible substrate materials, producing highly flexible, lightweight solar panels. Improvements in efficiency have made CIGS an established technology among alternative cell materials. | 1 | Semiconductor Materials |
Organic molecular wires usually consist aromatic rings connected by ethylene group or acetylene groups. Transition metal-mediated cross-coupling reactions are used to connect simple building blocks together in a convergent fashion to build organic molecular wires. For example, a simple oligo (phenylene ethylnylene) type molecular wire (B) was synthesized starting from readily available 1-bromo-4-iodobenzene (A). The final product was obtained through several steps of Sonogashira coupling reactions.
Other organic molecular wires include carbon nanotubes and DNA. Carbon nanotubes can be synthesized via various nano-technological approaches. DNA can be prepared by either step-wise DNA synthesis on solid-phase or by DNA-polymerase-catalyzed replication inside cells.
It was recently shown that pyridine and pyridine-derived polymers can form electronically conductive polyazaacetylene chains under simple ultraviolet irradiation, and that the common observation of "browning" of aged pyridine samples is due in part to the formation of molecular wires. The gels exhibited a transition between ionic conductivity and electronic conductivity on irradiation. | 1 | Semiconductor Materials |
The salt and ice challenge is an Internet challenge where participants pour salt on their bodies, usually on the arm, and ice is then placed on the salt. This causes a "burning" sensation similar to frost bite, and participants vie to withstand the pain for the longest time. The challenge can be recorded and posted on YouTube or other forms of social media.
The mixture of ice and salt create
eutectic frigorific mixture which can get as cold as .
The salt and ice challenge can quickly cause second- and third-degree injuries similar to frostbite or being burnt with the metal end of a lighter, as well as causing painful open sores to form on the skin. Due to the numbing sensation of the cold and possible nerve damage during the stunt, participants are often unaware of the extent of any injuries sustained during the challenge, only feeling pain once the salt on their skin enters lesions created during the challenge. Skin discoloration from the challenge may remain after the challenge has been attempted. | 0 | Salts |
The crystal structure of PtSi is orthorhombic, with each silicon atom having six neighboring platinum atoms. The distances between the silicon and the platinum neighbors are as follows: one at a distance of 2.41 angstroms, two at a distance of 2.43 angstroms, one at a distance of 2.52 angstroms, and the final two at a distance of 2.64 angstroms. Each platinum atom has six silicon neighbors at the same distances, as well as two platinum neighbors, at a distance of 2.87 and 2.90 angstroms. All of the distances over 2.50 angstroms are considered too far to really be involved in bonding interactions of the compound. As a result, it has been shown that two sets of covalent bonds compose the bonds forming the compound. One set is the three center Pt–Si–Pt bond, and the other set the two center Pt–Si bonds. Each silicon atom in the compound has one three center bond and two center bonds. The thinnest film of PtSi would consist of two alternating planes of atoms, a single sheet of orthorhombic structures. Thicker layers are formed by stacking pairs of the alternating sheets. The mechanism of bonding between PtSi is more similar to that of pure silicon than pure platinum or , though experimentation has revealed metallic bonding character in PtSi that pure silicon lacks. | 1 | Semiconductor Materials |
Solutions of electride salts are powerful reducing agents, as demonstrated by their use in the Birch reduction. Evaporation of these blue solutions affords a mirror of Na metal. If not evaporated, such solutions slowly lose their colour as the electrons reduce ammonia:
:2[Na(NH)]e → 2NaNH + 10NH + H
This conversion is catalyzed by various metals. An electride, [Na(NH)]e, is formed as a reaction intermediate. | 0 | Salts |
Copper(II) chloride is prepared commercially by the action of chlorination of copper. Copper at red heat (300-400°C) combines directly with chlorine gas, giving (molten) copper(II) chloride. The reaction is very exothermic.
A solution of copper(II) chloride is commercially produced by adding chlorine gas to a circulating mixture of hydrochloric acid and copper. From this solution, the dihydrate can be produced by evaporation.
Although copper metal itself cannot be oxidized by hydrochloric acid, copper-containing bases such as the hydroxide, oxide, or copper(II) carbonate can react to form in an acid-base reaction which can subsequently be heated above to produce the anhydrous derivative.
Once prepared, a solution of may be purified by crystallization. A standard method takes the solution mixed in hot dilute hydrochloric acid, and causes the crystals to form by cooling in a calcium chloride () ice bath.
There are indirect and rarely used means of using copper ions in solution to form copper(II) chloride. Electrolysis of aqueous sodium chloride with copper electrodes produces (among other things) a blue-green foam that can be collected and converted to the hydrate. While this is not usually done due to the emission of toxic chlorine gas, and the prevalence of the more general chloralkali process, the electrolysis will convert the copper metal to copper ions in solution forming the compound. Indeed, any solution of copper ions can be mixed with hydrochloric acid and made into a copper chloride by removing any other ions. | 1 | Semiconductor Materials |
Hollow nanospheres of cobalt oxide have been investigated as materials for gas sensor electrodes, for the detection of toluene, acetone, and other organic vapors.
Cobalt oxide nanoparticles anchored on single-walled carbon nanotubes have been investigated for sensing nitrogen oxides and hydrogen. This application takes advantage of the reactivity between the gas and the oxide, as well as the electrical connection with the substrate (both being p-type semiconductors). Nitrogen oxides react with the oxide as electron acceptors, reducing the electrode's resistance; whereas hydrogen acts as an electron donor, increasing the resistance. | 1 | Semiconductor Materials |
Xanthatic acids, with the formula ROC(S)SH, can be prepared by treating alkali metal xanthates, e.g. potassium ethyl xanthate, with hydrochloric acid at low temperatures. The methyl and ethyl xanthic acids are oils that are soluble in organic solvents. Benzyl xanthic acid is a solid. They have pKas near 2. These compounds thermally decompose in the presence of base to the alcohol and carbon disulfide.
Xanthic acids characteristically decompose:
:ROCSK + HCl → ROH + CS + KCl
This reaction is the reverse of the method for the preparation of the xanthate salts. The intermediate in the decomposition is the xanthic acid, ROC(S)SH, which can be isolated in certain cases. | 0 | Salts |
The counterion condensation originally only describes the behaviour of a charged rod. It competes here with Poisson-Boltzmann theory, which was shown to give less artificial results than the counterion condensation theories. | 0 | Salts |
Crystals of bismuth antimonides are synthesized by melting bismuth and antimony together under inert gas or vacuum. Zone melting is used to decrease the concentration of impurities. When synthesizing single crystals of bismuth antimonides, it is important that impurities are removed from the samples, as oxidation occurring at the impurities leads to polycrystalline growth. | 1 | Semiconductor Materials |
In 1914 black phosphorus, a layered, semiconducting allotrope of phosphorus, was synthesized. This allotrope exhibits high carrier mobility. In 2014, several groups isolated single-layer phosphorene, a monolayer of black phosphorus. It attracted renewed attention because of its potential in optoelectronics and electronics due to its band gap, which can be tuned via modifying its thickness, anisotropic photoelectronic properties and carrier mobility. Phosphorene was initially prepared using mechanical cleavage, a commonly used technique in graphene production.
In 2023, alloys of arsenic-phosphorene displayed higher hole mobility than pure phosphorene and were also magnetic. | 1 | Semiconductor Materials |
Gallium manganese arsenide, chemical formula is a magnetic semiconductor. It is based on the world's second most commonly used semiconductor, gallium arsenide, (chemical formula ), and readily compatible with existing semiconductor technologies. Differently from other dilute magnetic semiconductors, such as the majority of those based on II-VI semiconductors, it is not paramagnetic
but ferromagnetic, and hence exhibits hysteretic magnetization behavior. This memory effect is of importance for the creation of persistent devices. In , the manganese atoms provide a magnetic moment, and each also acts as an acceptor, making it a p-type material. The presence of carriers allows the material to be used for spin-polarized currents. In contrast, many other ferromagnetic magnetic semiconductors are strongly insulating
and so do not possess free carriers. is therefore a candidate material for spintronic devices but it is likely to remain only a testbed for basic research as its Curie temperature could only be raised up to approximatelly 200 K. | 1 | Semiconductor Materials |
Building stone containing pyrite tends to stain brown as pyrite oxidizes. This problem appears to be significantly worse if any marcasite is present. The presence of pyrite in the aggregate used to make concrete can lead to severe deterioration as pyrite oxidizes. In early 2009, problems with Chinese drywall imported into the United States after Hurricane Katrina were attributed to pyrite oxidation, followed by microbial sulfate reduction which released hydrogen sulfide gas (). These problems included a foul odor and corrosion of copper wiring. In the United States, in Canada, and more recently in Ireland, where it was used as underfloor infill, pyrite contamination has caused major structural damage. Concrete exposed to sulfate ions, or sulfuric acid, degrades by sulfate attack: the formation of expansive mineral phases, such as ettringite (small needle crystals exerting a huge crystallization pressure inside the concrete pores) and gypsum creates inner tensile forces in the concrete matrix which destroy the hardened cement paste, form cracks and fissures in concrete, and can lead to the ultimate ruin of the structure. Normalized tests for construction aggregate certify such materials as free of pyrite or marcasite. | 1 | Semiconductor Materials |
Xanthate anions also undergo alkylation to give xanthate esters, which are generally stable:
:ROCSK + R′X → ROC(S)SR′ + KX
The C-O bond in these compounds are susceptible to cleavage by the Barton–McCombie deoxygenation, which provides a means for deoxygenation of alcohols.
They can be oxidized to dixanthogen disulfides:
:2 ROCSNa + I → ROC(S)SC(S)OR + 2 NaI
Acylation of xanthates gives alkyl xanthogen esters (ROC(S)SC(O)R') and related anhydrides.
Xanthates bind to transition metal cations as bidentate ligands. The charge-neutral complexes are soluble in organic solvents.
Xanthates are intermediates in the Chugaev elimination process. They can be used to control radical polymerisation under the RAFT process, also termed MADIX (macromolecular design via interchange of xanthates). | 0 | Salts |
In the Zimmermann reaction the Janovski adduct is oxidized with excess base to a strongly colored enolate with subsequent reduction of the dinitro compound to the aromatic nitro amine. This reaction is the basis of the Zimmermann test used for the detection of ketosteroids. | 0 | Salts |
Heating powdered europium and red phosphorus in an inert atmosphere or vacuum:
:: 4 Eu + P → 4 EuP
Passing phosphine through a solution of europium in liquid ammonia:
:: Eu + 2PH → Eu(PH) + H
Eu(PH) is formed, which then decomposes to europium(III) phosphide and phosphine:
:: 2Eu(PH) → 2EuP + 2PH + H | 1 | Semiconductor Materials |
* African black soap, popular in West Africa
* Aleppo soap, popular in Syria
* Castile soap, popular in Spain
* Marseille soap, popular in France
* Moroccan black soap, popular in Morocco
* Nabulsi soap, popular in the West Bank
* Saltwater soap, used to wash in seawater
* Shaving soap, used for shaving
* Vegan soap, made without use of animal byproducts | 0 | Salts |
CuGaO exists in two main polymorphs, α and β. The α form has the delafossite crystal structure and can be prepared by reacting CuO with GaO at high temperatures. The β form has a wurtzite-like crystal structure (space group Pna2); it is metastable, but exhibits a long-term stability at temperatures below 300 °C. It can be obtained by an ion exchange of Na ions in a β-NaGaO precursor with Cu ions in CuCl under vacuum, to avoid the oxidation of Cu to Cu.
Unlike most I-III-VI oxides, which are transparent, electrically insulating solids with a bandgap above 2 eV, β-CuGaO has a direct bandgap of 1.47 eV, which is favorable for solar cell applications. In contrast, β-AgGaO and β-AgAlO have an indirect bandgap. Undoped β-CuGaO is a p-type semiconductor. | 1 | Semiconductor Materials |
CsAu is obtained by heating a stoichiometric mixture of caesium and gold. The two metallic-yellow liquids react to give a transparent yellow product. Despite being a compound of two metals, CsAu lacks metallic properties since it is a salt with localized charges; it instead behaves as a semiconductor with band gap 2.6 eV.
The compound hydrolyzes readily, yielding caesium hydroxide, metallic gold, and hydrogen.
:2 CsAu + 2 HO → 2 CsOH + 2 Au + H
The solution in liquid ammonia is brown, and the ammonia adduct is blue; the latter has ammonia molecules intercalated between layers of the CsAu crystal parallel to the (110) plane. Solutions undergo metathesis with tetramethylammonium loaded ion exchange resin to give tetramethylammonium auride. | 1 | Semiconductor Materials |
Layered electrides or electrenes are single-layer materials consisting of alternating atomically thin two-dimensional layers of electrons and ionized atoms. The first example was CaN, in which the charge (+4) of two calcium ions is balanced by the charge of a nitride ion (-3) in the ion layer plus a charge (-1) in the electron layer. | 0 | Salts |
Salts can be classified in a variety of ways. Salts that produce hydroxide ions when dissolved in water are called alkali salts and salts that produce hydrogen ions when dissolved in water are called acid salts. Neutral salts are those salts that are neither acidic nor alkaline. Zwitterions contain an anionic and a cationic centre in the same molecule, but are not considered salts. Examples of zwitterions are amino acids, many metabolites, peptides, and proteins. | 0 | Salts |
Due to their properties (primarily large, tuneable band gaps and efficient intercalation of salts) graphitic carbon nitrides are under research for a variety of applications:
* Photocatalysts
** Decomposition of water to H and O
** Degradation of pollutants
* Large band gap semiconductor
* Heterogeneous catalyst and support
** The significant resilience of carbon nitrides combined with surface and intralayer reactivities make them potentially useful catalysts relying on their labile protons and Lewis base functionalities. Modifications such as doping, protonation and molecular functionalisation can be exploited to improve selectivity and performance.
** Nanoparticle catalysts supported on gCN are under development for both proton exchange membrane fuel cells and water electrolyzers.
** Despite graphitic carbon nitride having some advantages, such as mild band gap (2.7 eV), absorption of visible light and flexibility, it still has limitations for practical applications due to low efficiency of visible light utilization, high recombination rate of the photo generated charge carriers, low electrical conductivity and small specific surface area (g). To modify these shortages, one of the most attractive approaches is doping graphitic carbon nitride with carbon nanomaterials, such as carbon nanotubes. First, carbon nanotubes have large specific surface area, so they can provide more sites to separate the charge carriers, then decrease the recombination rate of the charge carriers and further increase the activity of reduction reaction. Second, carbon nanotubes show high electron conducting ability, which means they can improve graphitic carbon nitride with visible light response, efficient charge carrier separation and transfer, thereby improving its electronic properties. Third, carbon nanotubes can be regarded as a kind of narrow band semiconductor material, also known as a photosensitizer, which can extend the range of the light absorption of semiconductor photocatalytic material, thereby enhancing its utilization of visible light.
* Energy Storage materials
** Due to the intercalation of Li being able to occur to more sites than for graphite due to intra layer voids in addition to intercalation between layers, gCN can store a large amount of Li making them potentially useful for rechargeable batteries. | 1 | Semiconductor Materials |
FeO is ferrimagnetic with a Curie temperature of . There is a phase transition at , called Verwey transition where there is a discontinuity in the structure, conductivity and magnetic properties. This effect has been extensively investigated and whilst various explanations have been proposed, it does not appear to be fully understood.
While it has much higher electrical resistivity than iron metal (96.1 nΩ m), FeO's electrical resistivity (0.3 mΩ m ) is significantly lower than that of FeO (approx kΩ m). This is ascribed to electron exchange between the Fe and Fe centres in FeO. | 1 | Semiconductor Materials |
There is considerable interest in using InS to replace the semiconductor CdS (cadmium sulfide) in photoelectronic devices. β-InS has a tunable band gap, which makes it attractive for photovoltaic applications, and it shows promise when used in conjunction with TiO in solar panels, indicating that it could replace CdS in that application as well. Cadmium sulfide is toxic and must be deposited with a chemical bath, but indium(III) sulfide shows few adverse biological effects and can be deposited as a thin film through less hazardous methods.
Thin films β-InS can be grown with varying band gaps, which make them widely applicable as photovoltaic semiconductors, especially in heterojunction solar cells.
Plates coated with beta-InS nanoparticles can be used efficiently for PEC (photoelectrochemical) water splitting. | 1 | Semiconductor Materials |
Indium oxide is used in some types of batteries, thin film infrared reflectors transparent for visible light (hot mirrors), some optical coatings, and some antistatic coatings. In combination with tin dioxide, indium oxide forms indium tin oxide (also called tin doped indium oxide or ITO), a material used for transparent conductive coatings.
In semiconductors, indium oxide can be used as an n-type semiconductor used as a resistive element in integrated circuits.
In histology, indium oxide is used as a part of some stain formulations. | 1 | Semiconductor Materials |
is commonly synthesized via a precipitation reaction between potassium iodide and lead(II) nitrate () in water solution:
While the potassium nitrate is soluble, the lead iodide is nearly insoluble at room temperature, and thus precipitates out.
Other soluble compounds containing lead(II) and iodide can be used instead, for example lead(II) acetate and sodium iodide.
The compound can also be synthesized by reacting iodine vapor with molten lead between 500 and 700 °C.
A thin film of can also be prepared by depositing a film of lead sulfide and exposing it to iodine vapor, by the reaction
The sulfur is then washed with dimethyl sulfoxide. | 1 | Semiconductor Materials |
Dithionitronium hexafluoroarsenate is prepared from thiazyl chloride using silver hexafluoroarsenate. The hexachloroantimonate salt can be prepared by treating thiazyl chloride with sulfur in the presence of antimony pentachloride according to this idealized equation:
The dithionitronium cation reacts with nitriles to give dithiadiazolium salts:
Addition to alkynes gives dithiazolium salts: | 0 | Salts |
Estropipate was marketed under the brand names Genoral, Harmogen, Improvera, Ogen, Ortho-Est, and Sulestrex among others. | 0 | Salts |
An ionomer () (iono- + -mer) is a polymer composed of repeat units of both electrically neutral repeating units and ionized units covalently bonded to the polymer backbone as pendant group moieties. Usually no more than 15 mole percent are ionized. The ionized units are often carboxylic acid groups.
The classification of a polymer as an ionomer depends on the level of substitution of ionic groups as well as how the ionic groups are incorporated into the polymer structure. For example, polyelectrolytes also have ionic groups covalently bonded to the polymer backbone, but have a much higher ionic group molar substitution level (usually greater than 80%); ionenes are polymers where ionic groups are part of the actual polymer backbone. These two classes of ionic-group-containing polymers have vastly different morphological and physical properties and are therefore not considered ionomers.
Ionomers have unique physical properties including electrical conductivity and viscosity—increase in ionomer solution viscosity with increasing temperatures (see conducting polymer). Ionomers also have unique morphological properties as the non-polar polymer backbone is energetically incompatible with the polar ionic groups. As a result, the ionic groups in most ionomers will undergo microphase separation to form ionic-rich domains.
Commercial applications for ionomers include golf ball covers, semipermeable membranes, sealing tape and thermoplastic elastomers. Common examples of ionomers include polystyrene sulfonate, Nafion and Hycar. | 0 | Salts |
Regardless of the fact that room-temperature ferromagnetism has not yet been achieved, magnetic semiconductors materials such as , have shown considerable success. Thanks to the rich interplay of physics inherent to magnetic semiconductors a variety of novel phenomena and device structures have been demonstrated. It is therefore instructive to make a critical review of these main developments.
A key result in magnetic semiconductors technology is gateable ferromagnetism, where an electric field is used to control the ferromagnetic properties. This was achieved by Ohno et al.
using an insulating-gate field-effect transistor with as the magnetic channel. The magnetic properties were inferred from magnetization dependent Hall measurements of the channel. Using the gate action to either deplete or accumulate holes in the channel it was possible to change the characteristic of the Hall response to be either that of a paramagnet or of a ferromagnet. When the temperature of the sample was close to its T it was possible to turn the ferromagnetism on or off by applying a gate voltage which could change the T by ±1K.
A similar transistor device was used to provide further examples of gateable ferromagnetism.
In this experiment the electric field was used to modify the coercive field at which magnetization reversal occurs. As a result of the dependence of the magnetic hysteresis on the gate bias the electric field could be used to assist magnetization reversal or even demagnetize the ferromagnetic material.
The combining of magnetic and electronic functionality demonstrated by this experiment is one of the goals of spintronics and may be expected to have a great technological impact.
Another important spintronic functionality that has been demonstrated in magnetic semiconductors is that of spin injection. This is where the high spin polarization inherent to these magnetic materials is used to transfer spin polarized carriers into a non-magnetic material.
In this example, a fully epitaxial heterostructure was used where spin polarized holes were injected from a layer to an (In,Ga)As quantum well where they combine with unpolarized electrons from an n-type substrate. A polarization of 8% was measured in the resulting electroluminescence. This is again of potential technological interest as it shows the possibility that the spin states in non-magnetic semiconductors can be manipulated without the application of a magnetic field.
offers an excellent material to study domain wall mechanics because the domains can have a size of the order of 100 μm.
Several studies have been done in which lithographically defined lateral constrictions
or other pinning points
are used to manipulate domain walls. These experiments are crucial to understanding domain wall nucleation and propagation which would be necessary for the creation of complex logic circuits based on domain wall mechanics.
Many properties of domain walls are still not fully understood and one particularly outstanding issue is of the magnitude and size of the resistance associated with current passing through domain walls. Both positive
and negative
values of domain wall resistance have been reported, leaving this an open area for future research.
An example of a simple device that utilizes pinned domain walls is provided by reference.
This experiment consisted of a lithographically defined narrow island connected to the leads via a pair of nanoconstrictions. While the device operated in a diffusive regime the constrictions would pin domain walls, resulting in a giant magnetoresistance signal. When the device operates in a tunnelling regime another magnetoresistance effect is observed, discussed below.
A furtherproperty of domain walls is that of current induced domain wall motion. This reversal is believed to occur as a result of the spin-transfer torque exerted by a spin polarized current.
It was demonstrated in reference
using a lateral device containing three regions which had been patterned to have different coercive fields, allowing the easy formation of a domain wall. The central region was designed to have the lowest coercivity so that the application of current pulses could cause the orientation of the magnetization to be switched. This experiment showed that the current required to achieve this reversal in was two orders of magnitude lower than that of metal systems. It has also been demonstrated that current-induced magnetization reversal can occur across a vertical tunnel junction.
Another novel spintronic effect, which was first observed in based tunnel devices, is tunnelling anisotropic magnetoresistance. This effect arises from the intricate dependence of the tunnelling density of states on the magnetization, and can result in magnetoresistance of several orders of magnitude. This was demonstrated first in vertical tunnelling structures
and then later in lateral devices.
This has established tunnelling anisotropic magnetoresistance as a generic property of ferromagnetic tunnel structures. Similarly, the dependence of the single electron charging energy on the magnetization has resulted in the observation of another dramatic magnetoresistance effect in a device, the so-called Coulomb blockade anisotropic magnetoresistance. | 1 | Semiconductor Materials |
Ionic compounds have long had a wide variety of uses and applications. Many minerals are ionic. Humans have processed common salt (sodium chloride) for over 8000 years, using it first as a food seasoning and preservative, and now also in manufacturing, agriculture, water conditioning, for de-icing roads, and many other uses. Many ionic compounds are so widely used in society that they go by common names unrelated to their chemical identity. Examples of this include borax, calomel, milk of magnesia, muriatic acid, oil of vitriol, saltpeter, and slaked lime.
Soluble ionic compounds like salt can easily be dissolved to provide electrolyte solutions. This is a simple way to control the concentration and ionic strength. The concentration of solutes affects many colligative properties, including increasing the osmotic pressure, and causing freezing-point depression and boiling-point elevation. Because the solutes are charged ions they also increase the electrical conductivity of the solution. The increased ionic strength reduces the thickness of the electrical double layer around colloidal particles, and therefore the stability of emulsions and suspensions.
The chemical identity of the ions added is also important in many uses. For example, fluoride containing compounds are dissolved to supply fluoride ions for water fluoridation.
Solid ionic compounds have long been used as paint pigments, and are resistant to organic solvents, but are sensitive to acidity or basicity. Since 1801 pyrotechnicians have described and widely used metal-containing ionic compounds as sources of colour in fireworks. Under intense heat, the electrons in the metal ions or small molecules can be excited. These electrons later return to lower energy states, and release light with a colour spectrum characteristic of the species present.
In chemistry, ionic compounds are often used as precursors for high-temperature solid-state synthesis.
Many metals are geologically most abundant as ionic compounds within ores. To obtain the elemental materials, these ores are processed by smelting or electrolysis, in which redox reactions occur (often with a reducing agent such as carbon) such that the metal ions gain electrons to become neutral atoms. | 0 | Salts |
Mercury(II) iodide is used for preparation of Nessler's reagent, used for detection of presence of ammonia.
Mercury(II) iodide is a semiconductor material, used in some x-ray and gamma ray detection and imaging devices operating at room temperatures.
In veterinary medicine, mercury(II) iodide is used in blister ointments in exostoses, bursal enlargement, etc.
It can appear as a precipitate in many reactions. | 1 | Semiconductor Materials |
In July 2020 scientists reported that they have observed a voltage-induced transformation of normally diamagnetic pyrite into a ferromagnetic material, which may lead to applications in devices such as solar cells or magnetic data storage.
Researchers at Trinity College Dublin, Ireland have demonstrated that FeS can be exfoliated into few-layers just like other two-dimensional layered materials such as graphene by a simple liquid-phase exfoliation route. This is the first study to demonstrate the production of non-layered 2D-platelets from 3D bulk FeS. Furthermore, they have used these 2D-platelets with 20% single walled carbon-nanotube as an anode material in lithium-ion batteries, reaching a capacity of 1000 mAh/g close to the theoretical capacity of FeS.
In 2021, a natural pyrite stone has been crushed and pre-treated followed by liquid-phase exfoliation into two-dimensional nanosheets, which has shown capacities of 1200 mAh/g as an anode in lithium-ion batteries. | 1 | Semiconductor Materials |
It is said to have potential for optical applications but the exploitation of this potential has been limited by the ability to readily grow single crystals Gallium selenide crystals show great promise as a nonlinear optical material and as a photoconductor. Non-linear optical materials are used in the frequency conversion of laser light. Frequency conversion involves the shifting of the wavelength of a monochromatic source of light, usually laser light, to a higher or lower wavelength of light that cannot be produced from a conventional laser source.
Several methods of frequency conversion using non-linear optical materials exist. Second harmonic generation leads to doubling of the frequency of infrared carbon dioxide lasers. In optical parametric generation, the wavelength of light is doubled. Near-infrared solid-state lasers are usually used in optical parametric generations.
One original problem with using gallium selenide in optics is that it is easily broken along cleavage lines and thus it can be hard to cut for practical application. It has been found, however, that doping the crystals with indium greatly enhances their structural strength and makes their application much more practical. There remain, however, difficulties with crystal growth that must be overcome before gallium selenide crystals may become more widely used in optics.
Single layers of gallium selenide are dynamically stable two-dimensional semiconductors, in which the valence band has an inverted Mexican-hat shape, leading to a Lifshitz transition as the hole-doping is increased.
The integration of gallium selenide into electronic devices has been hindered by its air sensitivity. Several approaches have been developed to encapsulate GaSe mono- and few-layers, leading to improved chemical stability and electronic mobility. | 1 | Semiconductor Materials |
The materials used in SWRO plants are dominated by non-metallic components and stainless steels, since lower operating temperatures allow the construction of desalination plants with more corrosion-resistant coatings. Therefore, the concentration values of heavy metals in the discharge of SWRO plants are much lower than the acute toxicity levels to generate environmental impacts on marine ecosystems. | 0 | Salts |
Halide compounds such as Potassium chloride|, Potassium bromide| and Potassium iodide| can be tested with silver nitrate solution, . The halogen will react with and form a precipitate, with varying colour depending on the halogen:
* Silver(I) fluoride|: no precipitate
* Silver chloride|: white
* Silver bromide|: creamy (pale yellow)
* Silver iodide|: green (yellow)
For organic compounds containing halides, the Beilstein test is used. | 0 | Salts |
Researchers have also constructed the CMOS inverter (logic circuit) by combining a phosphorene PMOS transistor with a MoS NMOS transistor, achieving high heterogeneous integration of semiconducting phosphorene crystals as a new channel material for potential electronic applications. In the inverter, the power supply voltage is set to be 1 V. The output voltage shows a clear transition from VDD to 0 within the input voltage range from −10 to −2 V. A maximum gain of ~1.4 is attained. | 1 | Semiconductor Materials |
NaH can ignite spontaneously in air. It also reacts vigorously with water or humid air to release hydrogen, which is very flammable, and sodium hydroxide (NaOH), a quite corrosive base. In practice, most sodium hydride is sold as a dispersion in mineral oil, which can be safely handled in air. Although sodium hydride is widely used in DMSO, DMF or DMAc for SN2 type reactions there have been many cases of fires and/or explosions from such mixtures. | 1 | Semiconductor Materials |
Aqueous solutions prepared from copper(II) chloride contain a range of copper(II) complexes depending on concentration, temperature, and the presence of additional chloride ions. These species include the blue color of and the yellow or red color of the halide complexes of the formula . | 1 | Semiconductor Materials |
and related molybdenum sulfides are efficient catalysts for hydrogen evolution, including the electrolysis of water; thus, are possibly useful to produce hydrogen for use in fuel cells. | 1 | Semiconductor Materials |
Copper(I) iodide can be prepared by heating iodine and copper in concentrated hydriodic acid.
In the laboratory however, copper(I) iodide is prepared by simply mixing an aqueous solution of potassium iodide and a soluble copper(II) salt such as copper(II) sulfate.
:Cu + 2I → CuI + 0.5I | 1 | Semiconductor Materials |
Although bismuth selenide occurs naturally (as the mineral guanajuatite) at the Santa Catarina Mine in Guanajuato, Mexico as well as some sites in the United States and Europe, such deposits are rare and contain a significant level of sulfur atoms as an impurity. For this reason, most bismuth selenide used in research into potential commercial applications is synthesized. Commercially-produced samples are available for use in research, but the concentration of selenium vacancies is heavily dependent upon growth conditions, and so bismuth selenide used for research is often synthesized in the laboratory.
A stoichiometric mixture of elemental bismuth and selenium, when heated above the melting points of these elements in the absence of air, will become a liquid that freezes to crystalline . Large single crystals of bismuth selenide can be prepared by the Bridgman–Stockbarger method. | 1 | Semiconductor Materials |
Salt tectonics, or halokinesis, or halotectonics, is concerned with the geometries and processes associated with the presence of significant thicknesses of evaporites containing rock salt within a stratigraphic sequence of rocks. This is due both to the low density of salt, which does not increase with burial, and its low strength.
Salt structures (excluding undeformed layers of salt) have been found in more than 120 sedimentary basins around the world. | 0 | Salts |
It is produced on a large scale by pyrometallurgy, as one stage in extracting copper from its ores. The ores are treated with an aqueous mixture of ammonium carbonate, ammonia, and oxygen to give copper(I) and copper(II) ammine complexes, which are extracted from the solids. These complexes are decomposed with steam to give CuO.
It can be formed by heating copper in air at around 300–800 °C:
: 2 Cu + O → 2 CuO
For laboratory uses, pure copper(II) oxide is better prepared by heating copper(II) nitrate, copper(II) hydroxide, or basic copper(II) carbonate:
: 2 Cu(NO) → 2 CuO + 4 NO + O (180°C)
: Cu(OH)CO → 2 CuO + CO + HO
: Cu(OH) → CuO + HO | 1 | Semiconductor Materials |
Elemental chlorine can be produced by electrolysis of brine (NaCl solution). This process also produces sodium hydroxide (NaOH) and Hydrogen gas (H). The reaction equations are as follows:
* Cathode:
* Anode:
* Overall process: | 0 | Salts |
In chemistry, a salt or ionic compound is a chemical compound consisting of an ionic assembly of positively charged cations and negatively charged anions, which results in a neutral compound with no net electric charge. The constituent ions are held together by electrostatic forces termed ionic bonds.
The component ions in a salt can be either inorganic, such as chloride (Cl), or organic, such as acetate (). Each ion can be either monatomic (termed simple ion), such as fluoride (F), and sodium (Na) and chloride (Cl) in sodium chloride, or polyatomic, such as sulfate (), and ammonium () and carbonate () ions in ammonium carbonate. Salt containing basic ions hydroxide (OH) or oxide (O) are classified as bases, for example sodium hydroxide.
Individual ions within a salt usually have multiple near
neighbours, so are not considered to be part of molecules, but instead part of a continuous three-dimensional network. Salts usually form crystalline structures when solid.
Salts composed of small ions typically have high melting and boiling points, and are hard and brittle. As solids they are almost always electrically insulating, but when melted or dissolved they become highly conductive, because the ions become mobile. Some salts have large cations, large anions, or both. In terms of their properties, such species often are more similar to organic compounds. | 0 | Salts |