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Karl Fischer Reagent
In analytical chemistry, Karl Fischer titration is a classic titration method that uses coulometric or volumetric titration to determine trace amounts of water in a sample. It was invented in 1935 by the German chemist Karl Fischer. Today, the titration is done with an automated Karl Fischer titrator. Chemical principle The elementary reaction responsible for water quantification in the Karl Fischer titration is oxidation of sulfur dioxide () with iodine: : H2O + SO2 + I2 → SO3 + 2 HI This elementary reaction consumes exactly one molar equivalent of water vs. iodine. Iodine is added to the solution until it is present in excess, marking the end point of the titration, which can be detected by potentiometry. The reaction is run in an alcohol solution containing a base, which consumes the sulfur trioxide and hydroiodic acid produced. Coulometric titration The main compartment of the titration cell contains the anode solution plus the analyte. The anode solution consists of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KF Titrator
KF or Kf may refer to: Businesses and brands: * KF Aerospace, a Canadian aerospace company ** KF Cargo, a Canadian cargo airline ** KF Defence Programs, a Canadian defense contractor * Korea Foundation * Air Belgium, an airline based in Belgium (IATA code KF) * Blue1, a defunct airline based in Finland (IATA code KF) * Kelly's Fuels, fuels merchant in Northern Ireland * Kettle Foods, a snack foods manufacturer * Kooperativa Förbundet, a cooperative Swedish retail chain * KrisFlyer, the frequent flyer program of Singapore Airlines * Kiwi Farms Games: * ''Katamari Forever'', a video game for the PlayStation 3 * ''Killing Floor'' (2009 video game), a cooperative survival horror video game Science and technology: * A member of the Mazda K engine family * Kalman filter, in mathematics * Potassium fluoride, a chemical substance * Kleinflansch, a quick release vacuum flange * Cryoscopic constant, Kf, related to freezing-point depression * Karl Fischer titration * Stability constant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methanol
Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical compound and the simplest aliphatic Alcohol (chemistry), alcohol, with the chemical formula (a methyl group linked to a hydroxyl group, often abbreviated as MeOH). It is a light, Volatility (chemistry), volatile, colorless and flammable liquid with a distinctive alcoholic odor similar to that of ethanol (potable alcohol), but is more acutely toxic than the latter. Methanol acquired the name wood alcohol because it was once produced through destructive distillation of wood. Today, methanol is mainly produced industrially by hydrogenation of carbon monoxide. Methanol consists of a methyl group linked to a polar hydroxyl group. With more than 20 million tons produced annually, it is used as a Precursor (chemistry), precursor to other commodity chemicals, including formaldehyde, acetic acid, methyl tert-butyl ether, methyl ''tert''-butyl ether, methyl benzoate, anisole, peroxyacids, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titration
Titration (also known as titrimetry and volumetric analysis) is a common laboratory method of Quantitative research, quantitative Analytical chemistry, chemical analysis to determine the concentration of an identified analyte (a substance to be analyzed). A reagent, termed the ''titrant'' or ''titrator'', is prepared as a standard solution of known concentration and volume. The titrant reacts with a Solution (chemistry), solution of ''analyte'' (which may also be termed the ''titrand'') to determine the analyte's concentration. The volume of titrant that reacted with the analyte is termed the ''titration volume''. History and etymology The word "titration" descends from the French word ''titrer'' (1543), meaning the proportion of gold or silver in coins or in works of gold or silver; i.e., a measure of fineness or purity. ''Tiltre'' became ''titre'', which thus came to mean the "fineness of alloyed gold", and then the "concentration of a substance in a given sample". In 1828, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimethylacetamide
Dimethylacetamide (DMAc or DMA) is the organic compound with the formula CH3C(O)N(CH3)2. This colorless, water-miscible, high-boiling liquid is commonly used as a polar solvent in organic synthesis. DMA is miscible with most other solvents, although it is poorly soluble in aliphatic hydrocarbons. Synthesis and production DMA is prepared commercially by the reaction of dimethylamine with acetic anhydride or acetic acid. Dehydration of the salt of dimethylamine and acetic acid also furnishes this compound: : CH3CO2H·HN(CH3)2 → H2O + CH3CON(CH3)2 Dimethylacetamide can also be produced by the reaction of dimethylamine with methyl acetate. : The separation and purification of the product is carried out by multistage distillation in rectification columns. DMA is obtained with essentially quantitive (99%) yield referred to methyl acetate. Reactions and applications The chemical reactions of dimethylacetamide are typical of ''N'',''N''-disubstituted amides. Hydrolysis of the acyl- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithium Chloride
Lithium chloride is a chemical compound with the formula Li Cl. The salt is a typical ionic compound (with certain covalent characteristics), although the small size of the Li+ ion gives rise to properties not seen for other alkali metal chlorides, such as extraordinary solubility in polar solvents (83.05 g/100 mL of water at 20 °C) and its hygroscopic properties. Chemical properties The salt forms crystalline hydrates, unlike the other alkali metal chlorides. Mono-, tri-, and pentahydrates are known. The anhydrous salt can be regenerated by heating the hydrates. LiCl also absorbs up to four equivalents of ammonia/mol. As with any other ionic chloride, solutions of lithium chloride can serve as a source of chloride ion, e.g., forming a precipitate upon treatment with silver nitrate: : LiCl + AgNO3 → AgCl + LiNO3 Preparation Lithium chloride is produced by treatment of lithium carbonate with hydrochloric acid. Anhydrous LiCl is prepared from the hydrate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-shear Mixer
A high-shear mixer disperses, or transports, one phase or ingredient (liquid, solid, gas) into a main continuous phase (liquid), with which it would normally be immiscible. A rotor or impeller, together with a stationary component known as a stator, or an array of rotors and stators, is used either in a tank containing the solution to be mixed, or in a pipe through which the solution passes, to create shear. A high-shear mixer can be used to create emulsions, suspensions, lyosols (gas dispersed in liquid), and granular products. It is used in the adhesives, chemical, cosmetic, food, pharmaceutical, and plastics industries for emulsification, homogenization, particle size reduction, and dispersion. Principles of work Fluid undergoes shear when one area of fluid travels with a different velocity relative to an adjacent area. A high-shear mixer uses a rotating impeller or high-speed rotor, or a series of such impellers or inline rotors, usually powered by an electric motor, to " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coulometer
A voltameter or coulometer is a scientific instrument used for measuring instrument, measuring electric charge (quantity of electricity) through electrolytic action. The International System of Units, SI unit of electric charge is the coulomb. The voltameter should not be confused with a voltmeter, which measures electric potential. The SI unit for electric potential is the volt. Etymology Michael Faraday used an apparatus that he termed a "volta-electrometer"; subsequently John Frederic Daniell called this a "voltameter".Frank A. J. L. James, (1991), ''The correspondence of Michael Faraday'', IET, , letter 872, 9/1/1836 Types The voltameter is an electrolytic cell and the measurement is made by weighing the chemical element, element deposited or released at the cathode in a specified time. Silver voltameter This is the most accurate type. It consists of two silver plates in a solution of silver nitrate. When current is flowing, silver dissolves at the anode and is deposite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimethyl Sulfoxide
Dimethyl sulfoxide (DMSO) is an organosulfur compound with the formula . This colorless liquid is the sulfoxide most widely used commercially. It is an important polar aprotic solvent that dissolves both polar and nonpolar compounds and is miscible in a wide range of organic solvents as well as water. It has a relatively high boiling point. DMSO is metabolised to compounds that leave a garlic-like taste in the mouth after DMSO is absorbed by skin. In terms of chemical structure, the molecule has idealized Cs symmetry. It has a trigonal pyramidal molecular geometry consistent with other three-coordinate S(IV) compounds, with a nonbonded electron pair on the approximately tetrahedral sulfur atom. Synthesis and production Dimethyl sulfoxide was first synthesized in 1866 by the Russian scientist Alexander Zaytsev, who reported his findings in 1867. Its modern use as an industrial solvent began through popularization by Thor Smedslund at the Stepan Chemical Company. Dimeth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volatility (chemistry)
In chemistry, volatility is a material quality which describes how readily a substance vaporizes. At a given temperature and pressure, a substance with high volatility is more likely to exist as a vapour, while a substance with low volatility is more likely to be a liquid or solid. Volatility can also describe the tendency of a vapor to condense into a liquid or solid; less volatile substances will more readily condense from a vapor than highly volatile ones. Differences in volatility can be observed by comparing how fast substances within a group evaporate (or sublimate in the case of solids) when exposed to the atmosphere. A highly volatile substance such as rubbing alcohol (isopropyl alcohol) will quickly evaporate, while a substance with low volatility such as vegetable oil will remain condensed. In general, solids are much less volatile than liquids, but there are some exceptions. Solids that sublimate (change directly from solid to vapor) such as dry ice (solid carbon di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyridine
Pyridine is a basic (chemistry), basic heterocyclic compound, heterocyclic organic compound with the chemical formula . It is structurally related to benzene, with one methine group replaced by a nitrogen atom . It is a highly flammable, weakly alkaline, water-miscible liquid with a distinctive, unpleasant fish-like smell. Pyridine is colorless, but older or impure samples can appear yellow, due to the formation of extended, unsaturated Polymer, polymeric chains, which show significant electrical conductivity. The pyridine ring occurs in many important compounds, including agrochemicals, pharmaceuticals, and vitamins. Historically, pyridine was produced from coal tar. As of 2016, it is synthesized on the scale of about 20,000 tons per year worldwide. Properties Physical properties Pyridine is diamagnetism, diamagnetic. Its critical point (thermodynamics), critical parameters are: pressure 5.63 MPa, temperature 619 K and volume 248 cm3/mol. In the temperatur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bipotentiometric Titration
In analytical chemistry, potentiometric titration is a technique similar to direct titration of a redox reaction. It is a useful means of characterizing an acid. No indicator is used; instead the electric potential is measured across the analyte, typically an electrolyte solution. To do this, two electrodes are used, an indicator electrode (the glass electrode and metal ion indicator electrode) and a reference electrode. Reference electrodes generally used are hydrogen electrodes, calomel electrodes, and silver chloride electrodes. The indicator electrode forms an electrochemical half-cell with the ions of interest in the test solution. The reference electrode forms the other half-cell. The overall electric potential is calculated as :E_ = E_ - E_ + E_. is the potential drop over the test solution between the two electrodes. is recorded at intervals as the titrant is added. A graph of potential against volume added can be drawn and the end point of the reaction is halfway betw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cathode
A cathode is the electrode from which a conventional current leaves a polarized electrical device such as a lead-acid battery. This definition can be recalled by using the mnemonic ''CCD'' for ''Cathode Current Departs''. Conventional current describes the direction in which positive charges move. Electrons, which are the carriers of current in most electrical systems, have a negative electrical charge, so the movement of electrons is ''opposite'' to that of the conventional current flow: this means that electrons flow ''into'' the device's cathode from the external circuit. For example, the end of a household battery marked with a + (plus) is the cathode. The electrode through which conventional current flows the other way, into the device, is termed an anode. Charge flow Conventional current flows from cathode to anode outside the cell or device (with electrons moving in the opposite direction), regardless of the cell or device type and operating mode. Cathode polarity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
