1.
Jmol
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Jmol is computer software for molecular modelling chemical structures in 3-dimensions. Jmol returns a 3D representation of a molecule that may be used as a teaching tool and it is written in the programming language Java, so it can run on the operating systems Windows, macOS, Linux, and Unix, if Java is installed. It is free and open-source software released under a GNU Lesser General Public License version 2.0, a standalone application and a software development kit exist that can be integrated into other Java applications, such as Bioclipse and Taverna. A popular feature is an applet that can be integrated into web pages to display molecules in a variety of ways, for example, molecules can be displayed as ball-and-stick models, space-filling models, ribbon diagrams, etc. Jmol supports a range of chemical file formats, including Protein Data Bank, Crystallographic Information File, MDL Molfile. There is also a JavaScript-only version, JSmol, that can be used on computers with no Java, the Jmol applet, among other abilities, offers an alternative to the Chime plug-in, which is no longer under active development. While Jmol has many features that Chime lacks, it does not claim to reproduce all Chime functions, most notably, Chime requires plug-in installation and Internet Explorer 6.0 or Firefox 2.0 on Microsoft Windows, or Netscape Communicator 4.8 on Mac OS9. Jmol requires Java installation and operates on a variety of platforms. For example, Jmol is fully functional in Mozilla Firefox, Internet Explorer, Opera, Google Chrome, fast and Scriptable Molecular Graphics in Web Browsers without Java3D
2.
ChemSpider
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ChemSpider is a database of chemicals. ChemSpider is owned by the Royal Society of Chemistry, the database contains information on more than 50 million molecules from over 500 data sources including, Each chemical is given a unique identifier, which forms part of a corresponding URL. This is an approach to develop an online chemistry database. The search can be used to widen or restrict already found results, structure searching on mobile devices can be done using free apps for iOS and for the Android. The ChemSpider database has been used in combination with text mining as the basis of document markup. The result is a system between chemistry documents and information look-up via ChemSpider into over 150 data sources. ChemSpider was acquired by the Royal Society of Chemistry in May,2009, prior to the acquisition by RSC, ChemSpider was controlled by a private corporation, ChemZoo Inc. The system was first launched in March 2007 in a release form. ChemSpider has expanded the generic support of a database to include support of the Wikipedia chemical structure collection via their WiChempedia implementation. A number of services are available online. SyntheticPages is an interactive database of synthetic chemistry procedures operated by the Royal Society of Chemistry. Users submit synthetic procedures which they have conducted themselves for publication on the site and these procedures may be original works, but they are more often based on literature reactions. Citations to the published procedure are made where appropriate. They are checked by an editor before posting. The pages do not undergo formal peer-review like a journal article. The comments are moderated by scientific editors. The intention is to collect practical experience of how to conduct useful chemical synthesis in the lab, while experimental methods published in an ordinary academic journal are listed formally and concisely, the procedures in ChemSpider SyntheticPages are given with more practical detail. Comments by submitters are included as well, other publications with comparable amounts of detail include Organic Syntheses and Inorganic Syntheses
3.
PubChem
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PubChem is a database of chemical molecules and their activities against biological assays. The system is maintained by the National Center for Biotechnology Information, a component of the National Library of Medicine, PubChem can be accessed for free through a web user interface. Millions of compound structures and descriptive datasets can be downloaded via FTP. PubChem contains substance descriptions and small molecules with fewer than 1000 atoms and 1000 bonds, more than 80 database vendors contribute to the growing PubChem database. PubChem consists of three dynamically growing primary databases, as of 28 January 2016, Compounds,82.6 million entries, contains pure and characterized chemical compounds. Substances,198 million entries, contains also mixtures, extracts, complexes, bioAssay, bioactivity results from 1.1 million high-throughput screening programs with several million values. PubChem contains its own online molecule editor with SMILES/SMARTS and InChI support that allows the import and export of all common chemical file formats to search for structures and fragments. In the text search form the database fields can be searched by adding the name in square brackets to the search term. A numeric range is represented by two separated by a colon. The search terms and field names are case-insensitive, parentheses and the logical operators AND, OR, and NOT can be used. AND is assumed if no operator is used, example,0,5000,50,10 -5,5 PubChem was released in 2004. The American Chemical Society has raised concerns about the publicly supported PubChem database and they have a strong interest in the issue since the Chemical Abstracts Service generates a large percentage of the societys revenue. To advocate their position against the PubChem database, ACS has actively lobbied the US Congress, soon after PubChems creation, the American Chemical Society lobbied U. S. Congress to restrict the operation of PubChem, which they asserted competes with their Chemical Abstracts Service
4.
International Chemical Identifier
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Initially developed by IUPAC and NIST from 2000 to 2005, the format and algorithms are non-proprietary. The continuing development of the standard has supported since 2010 by the not-for-profit InChI Trust. The current version is 1.04 and was released in September 2011, prior to 1.04, the software was freely available under the open source LGPL license, but it now uses a custom license called IUPAC-InChI Trust License. Not all layers have to be provided, for instance, the layer can be omitted if that type of information is not relevant to the particular application. InChIs can thus be seen as akin to a general and extremely formalized version of IUPAC names and they can express more information than the simpler SMILES notation and differ in that every structure has a unique InChI string, which is important in database applications. Information about the 3-dimensional coordinates of atoms is not represented in InChI, the InChI algorithm converts input structural information into a unique InChI identifier in a three-step process, normalization, canonicalization, and serialization. The InChIKey, sometimes referred to as a hashed InChI, is a fixed length condensed digital representation of the InChI that is not human-understandable. The InChIKey specification was released in September 2007 in order to facilitate web searches for chemical compounds and it should be noted that, unlike the InChI, the InChIKey is not unique, though collisions can be calculated to be very rare, they happen. In January 2009 the final 1.02 version of the InChI software was released and this provided a means to generate so called standard InChI, which does not allow for user selectable options in dealing with the stereochemistry and tautomeric layers of the InChI string. The standard InChIKey is then the hashed version of the standard InChI string, the standard InChI will simplify comparison of InChI strings and keys generated by different groups, and subsequently accessed via diverse sources such as databases and web resources. Every InChI starts with the string InChI= followed by the version number and this is followed by the letter S for standard InChIs. The remaining information is structured as a sequence of layers and sub-layers, the layers and sub-layers are separated by the delimiter / and start with a characteristic prefix letter. The six layers with important sublayers are, Main layer Chemical formula and this is the only sublayer that must occur in every InChI. The atoms in the formula are numbered in sequence, this sublayer describes which atoms are connected by bonds to which other ones. Describes how many hydrogen atoms are connected to each of the other atoms, the condensed,27 character standard InChIKey is a hashed version of the full standard InChI, designed to allow for easy web searches of chemical compounds. Most chemical structures on the Web up to 2007 have been represented as GIF files, the full InChI turned out to be too lengthy for easy searching, and therefore the InChIKey was developed. With all databases currently having below 50 million structures, such duplication appears unlikely at present, a recent study more extensively studies the collision rate finding that the experimental collision rate is in agreement with the theoretical expectations. Example, Morphine has the structure shown on the right, as the InChI cannot be reconstructed from the InChIKey, an InChIKey always needs to be linked to the original InChI to get back to the original structure
5.
Simplified molecular-input line-entry system
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The simplified molecular-input line-entry system is a specification in form of a line notation for describing the structure of chemical species using short ASCII strings. SMILES strings can be imported by most molecule editors for conversion back into two-dimensional drawings or three-dimensional models of the molecules, the original SMILES specification was initiated in the 1980s. It has since modified and extended. In 2007, a standard called OpenSMILES was developed in the open-source chemistry community. Other linear notations include the Wiswesser Line Notation, ROSDAL and SLN, the original SMILES specification was initiated by David Weininger at the USEPA Mid-Continent Ecology Division Laboratory in Duluth in the 1980s. The Environmental Protection Agency funded the project to develop SMILES. It has since modified and extended by others, most notably by Daylight Chemical Information Systems. In 2007, a standard called OpenSMILES was developed by the Blue Obelisk open-source chemistry community. Other linear notations include the Wiswesser Line Notation, ROSDAL and SLN, in July 2006, the IUPAC introduced the InChI as a standard for formula representation. SMILES is generally considered to have the advantage of being slightly more human-readable than InChI, the term SMILES refers to a line notation for encoding molecular structures and specific instances should strictly be called SMILES strings. However, the term SMILES is also used to refer to both a single SMILES string and a number of SMILES strings, the exact meaning is usually apparent from the context. The terms canonical and isomeric can lead to confusion when applied to SMILES. The terms describe different attributes of SMILES strings and are not mutually exclusive, typically, a number of equally valid SMILES strings can be written for a molecule. For example, CCO, OCC and CC all specify the structure of ethanol, algorithms have been developed to generate the same SMILES string for a given molecule, of the many possible strings, these algorithms choose only one of them. This SMILES is unique for each structure, although dependent on the algorithm used to generate it. These algorithms first convert the SMILES to a representation of the molecular structure. A common application of canonical SMILES is indexing and ensuring uniqueness of molecules in a database, there is currently no systematic comparison across commercial software to test if such flaws exist in those packages. SMILES notation allows the specification of configuration at tetrahedral centers, and these are structural features that cannot be specified by connectivity alone and SMILES which encode this information are termed isomeric SMILES
6.
Chemical formula
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These are limited to a single typographic line of symbols, which may include subscripts and superscripts. A chemical formula is not a name, and it contains no words. Although a chemical formula may imply certain simple chemical structures, it is not the same as a full chemical structural formula. Chemical formulas can fully specify the structure of only the simplest of molecules and chemical substances, the simplest types of chemical formulas are called empirical formulas, which use letters and numbers indicating the numerical proportions of atoms of each type. Molecular formulas indicate the numbers of each type of atom in a molecule. For example, the formula for glucose is CH2O, while its molecular formula is C6H12O6. This is possible if the relevant bonding is easy to show in one dimension, an example is the condensed molecular/chemical formula for ethanol, which is CH3-CH2-OH or CH3CH2OH. For reasons of structural complexity, there is no condensed chemical formula that specifies glucose, chemical formulas may be used in chemical equations to describe chemical reactions and other chemical transformations, such as the dissolving of ionic compounds into solution. A chemical formula identifies each constituent element by its chemical symbol, in empirical formulas, these proportions begin with a key element and then assign numbers of atoms of the other elements in the compound, as ratios to the key element. For molecular compounds, these numbers can all be expressed as whole numbers. For example, the formula of ethanol may be written C2H6O because the molecules of ethanol all contain two carbon atoms, six hydrogen atoms, and one oxygen atom. Some types of compounds, however, cannot be written with entirely whole-number empirical formulas. An example is boron carbide, whose formula of CBn is a variable non-whole number ratio with n ranging from over 4 to more than 6.5. When the chemical compound of the consists of simple molecules. These types of formulas are known as molecular formulas and condensed formulas. A molecular formula enumerates the number of atoms to reflect those in the molecule, so that the formula for glucose is C6H12O6 rather than the glucose empirical formula. However, except for very simple substances, molecular chemical formulas lack needed structural information, for simple molecules, a condensed formula is a type of chemical formula that may fully imply a correct structural formula. For example, ethanol may be represented by the chemical formula CH3CH2OH
7.
Density
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The density, or more precisely, the volumetric mass density, of a substance is its mass per unit volume. The symbol most often used for density is ρ, although the Latin letter D can also be used. Mathematically, density is defined as mass divided by volume, ρ = m V, where ρ is the density, m is the mass, and V is the volume. In some cases, density is defined as its weight per unit volume. For a pure substance the density has the numerical value as its mass concentration. Different materials usually have different densities, and density may be relevant to buoyancy, purity, osmium and iridium are the densest known elements at standard conditions for temperature and pressure but certain chemical compounds may be denser. Thus a relative density less than one means that the floats in water. The density of a material varies with temperature and pressure and this variation is typically small for solids and liquids but much greater for gases. Increasing the pressure on an object decreases the volume of the object, increasing the temperature of a substance decreases its density by increasing its volume. In most materials, heating the bottom of a results in convection of the heat from the bottom to the top. This causes it to rise relative to more dense unheated material, the reciprocal of the density of a substance is occasionally called its specific volume, a term sometimes used in thermodynamics. Density is a property in that increasing the amount of a substance does not increase its density. Archimedes knew that the irregularly shaped wreath could be crushed into a cube whose volume could be calculated easily and compared with the mass, upon this discovery, he leapt from his bath and ran naked through the streets shouting, Eureka. As a result, the term eureka entered common parlance and is used today to indicate a moment of enlightenment, the story first appeared in written form in Vitruvius books of architecture, two centuries after it supposedly took place. Some scholars have doubted the accuracy of this tale, saying among other things that the method would have required precise measurements that would have been difficult to make at the time, from the equation for density, mass density has units of mass divided by volume. As there are units of mass and volume covering many different magnitudes there are a large number of units for mass density in use. The SI unit of kilogram per metre and the cgs unit of gram per cubic centimetre are probably the most commonly used units for density.1,000 kg/m3 equals 1 g/cm3. In industry, other larger or smaller units of mass and or volume are often more practical, see below for a list of some of the most common units of density
8.
Boiling point
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The boiling point of a substance is the temperature at which the vapor pressure of the liquid equals the pressure surrounding the liquid and the liquid changes into a vapor. The boiling point of a liquid varies depending upon the environmental pressure. A liquid in a vacuum has a lower boiling point than when that liquid is at atmospheric pressure. A liquid at high pressure has a boiling point than when that liquid is at atmospheric pressure. For a given pressure, different liquids boil at different temperatures, for example, water boils at 100 °C at sea level, but at 93.4 °C at 2,000 metres altitude. The normal boiling point of a liquid is the case in which the vapor pressure of the liquid equals the defined atmospheric pressure at sea level,1 atmosphere. At that temperature, the pressure of the liquid becomes sufficient to overcome atmospheric pressure. The standard boiling point has been defined by IUPAC since 1982 as the temperature at which boiling occurs under a pressure of 1 bar, the heat of vaporization is the energy required to transform a given quantity of a substance from a liquid into a gas at a given pressure. Liquids may change to a vapor at temperatures below their boiling points through the process of evaporation, evaporation is a surface phenomenon in which molecules located near the liquids edge, not contained by enough liquid pressure on that side, escape into the surroundings as vapor. On the other hand, boiling is a process in which molecules anywhere in the liquid escape, a saturated liquid contains as much thermal energy as it can without boiling. The saturation temperature is the temperature for a corresponding saturation pressure at which a liquid boils into its vapor phase, the liquid can be said to be saturated with thermal energy. Any addition of energy results in a phase transition. If the pressure in a system remains constant, a vapor at saturation temperature will begin to condense into its liquid phase as thermal energy is removed, similarly, a liquid at saturation temperature and pressure will boil into its vapor phase as additional thermal energy is applied. The boiling point corresponds to the temperature at which the pressure of the liquid equals the surrounding environmental pressure. Thus, the point is dependent on the pressure. Boiling points may be published with respect to the NIST, USA standard pressure of 101.325 kPa, at higher elevations, where the atmospheric pressure is much lower, the boiling point is also lower. The boiling point increases with increased pressure up to the critical point, the boiling point cannot be increased beyond the critical point. Likewise, the point decreases with decreasing pressure until the triple point is reached
9.
Solubility
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Solubility is the property of a solid, liquid, or gaseous chemical substance called solute to dissolve in a solid, liquid, or gaseous solvent. The solubility of a substance depends on the physical and chemical properties of the solute and solvent as well as on temperature, pressure. The solubility of a substance is a different property from the rate of solution. Most often, the solvent is a liquid, which can be a substance or a mixture. One may also speak of solid solution, but rarely of solution in a gas, the extent of solubility ranges widely, from infinitely soluble such as ethanol in water, to poorly soluble, such as silver chloride in water. The term insoluble is often applied to poorly or very poorly soluble compounds, a common threshold to describe something as insoluble is less than 0.1 g per 100 mL of solvent. Under certain conditions, the solubility can be exceeded to give a so-called supersaturated solution. Metastability of crystals can also lead to apparent differences in the amount of a chemical that dissolves depending on its form or particle size. A supersaturated solution generally crystallises when seed crystals are introduced and rapid equilibration occurs, phenylsalicylate is one such simple observable substance when fully melted and then cooled below its fusion point. Solubility is not to be confused with the ability to dissolve a substance, for example, zinc dissolves in hydrochloric acid as a result of a chemical reaction releasing hydrogen gas in a displacement reaction. The zinc ions are soluble in the acid, the smaller a particle is, the faster it dissolves although there are many factors to add to this generalization. Crucially solubility applies to all areas of chemistry, geochemistry, inorganic, physical, organic, in all cases it will depend on the physical conditions and the enthalpy and entropy directly relating to the solvents and solutes concerned. By far the most common solvent in chemistry is water which is a solvent for most ionic compounds as well as a range of organic substances. This is a factor in acidity/alkalinity and much environmental and geochemical work. According to the IUPAC definition, solubility is the composition of a saturated solution expressed as a proportion of a designated solute in a designated solvent. Solubility may be stated in units of concentration such as molarity, molality, mole fraction, mole ratio, mass per volume. Solubility occurs under dynamic equilibrium, which means that solubility results from the simultaneous and opposing processes of dissolution, the solubility equilibrium occurs when the two processes proceed at a constant rate. The term solubility is used in some fields where the solute is altered by solvolysis
10.
GHS hazard pictograms
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Hazard pictograms form part of the international Globally Harmonized System of Classification and Labelling of Chemicals. Two sets of pictograms are included within the GHS, one for the labelling of containers and for workplace hazard warnings, either one or the other is chosen, depending on the target audience, but the two are not used together. The two sets of use the same symbols for the same hazards, although certain symbols are not required for transport pictograms. Transport pictograms come in variety of colors and may contain additional information such as a subcategory number. It has still to be implemented by the European Union in 2009, the following pictograms are included in the Worldwide Model Using but have not been incorporated into the GHS, ICZ and Catwallsh Hazcom Labelling because of the nature of the hazards. Globally Harmonized System of Classification and Labelling of Chemicals, New York and Geneva, United Nations,2007, ISBN 978-92-1-116957-7, ST/SG/AC. 10/30/Rev. Model Regulations, New York and Geneva, United Nations,2007, ISBN 978-92-1-139120-6, manual of Tests and Criteria, New York and Geneva, United Nations,2002, ISBN 92-1-139087-7, ST/SG/AC. 10/11/Rev.4 GHS pictogram gallery from the United Nations Economic Commission for Europe
11.
Flash point
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The flash point is the lowest temperature at which vapours of a volatile material will ignite, when given an ignition source. The flash point may sometimes be confused with the autoignition temperature, the fire point is the lowest temperature at which the vapor will keep burning after being ignited and the ignition source removed. The fire point is higher than the point, because at the flash point the vapor may be reliably expected to cease burning when the ignition source is removed. The flash point is a characteristic that is used to distinguish between flammable liquids, such as petrol, and combustible liquids, such as diesel. It is also used to characterize the fire hazards of liquids, all liquids have a specific vapor pressure, which is a function of that liquids temperature and is subject to Boyles Law. As temperature increases, vapor pressure increases, as vapor pressure increases, the concentration of vapor of a flammable or combustible liquid in the air increases. Hence, temperature determines the concentration of vapor of the liquid in the air. The flash point is the lowest temperature at which there will be enough flammable vapor to induce ignition when a source is applied. There are two types of flash point measurement, open cup and closed cup. In open cup devices, the sample is contained in a cup which is heated and, at intervals. The measured flash point will vary with the height of the flame above the liquid surface and, at sufficient height. The best-known example is the Cleveland open cup, in both these types, the cups are sealed with a lid through which the ignition source can be introduced. Closed cup testers normally give lower values for the point than open cup and are a better approximation to the temperature at which the vapour pressure reaches the lower flammable limit. The flash point is an empirical measurement rather than a physical parameter. The measured value will vary with equipment and test protocol variations, including temperature ramp rate, time allowed for the sample to equilibrate, sample volume, methods for determining the flash point of a liquid are specified in many standards. For example, testing by the Pensky-Martens closed cup method is detailed in ASTM D93, IP34, ISO2719, DIN51758, JIS K2265 and AFNOR M07-019. Determination of flash point by the Small Scale closed cup method is detailed in ASTM D3828 and D3278, EN ISO3679 and 3680, cEN/TR15138 Guide to Flash Point Testing and ISO TR29662 Guidance for Flash Point Testing cover the key aspects of flash point testing. Gasoline is a used in a spark-ignition engine
12.
Haloalkane
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The haloalkanes are a group of chemical compounds derived from alkanes containing one or more halogens. They are a subset of the class of halocarbons, although the distinction is not often made. Haloalkanes are widely used commercially and, consequently, are known under many chemical and commercial names and they are used as flame retardants, fire extinguishants, refrigerants, propellants, solvents, and pharmaceuticals. Subsequent to the use in commerce, many halocarbons have also been shown to be serious pollutants. For example, the chlorofluorocarbons have been shown to lead to ozone depletion, methyl bromide is a controversial fumigant. Only haloalkanes which contain chlorine, bromine, and iodine are a threat to the ozone layer, haloalkane or alkyl halides are the compounds which have the general formula RX where R is an alkyl or substituted alkyl group and X is a halogen. Haloalkanes have been known for centuries, chloroethane was produced synthetically in the 15th century. The systematic synthesis of such compounds developed in the 19th century in step with the development of organic chemistry, methods were developed for the selective formation of C-halogen bonds. Especially versatile methods included the addition of halogens to alkenes, hydrohalogenation of alkenes, while most haloalkanes are human-produced, non-artificial-source haloalkanes do occur on Earth, mostly through enzyme-mediated synthesis by bacteria, fungi, and especially sea macroalgae. More than 1600 halogenated organics have been identified, with bromoalkanes being the most common haloalkanes, brominated organics in biology range from biologically produced methyl bromide to non-alkane aromatics and unsaturates. Halogenated alkanes in land plants are rare, but do occur. Specific dehalogenase enzymes in bacteria which remove halogens from haloalkanes, are also known, from the structural perspective, haloalkanes can be classified according to the connectivity of the carbon atom to which the halogen is attached. In primary haloalkanes, the carbon that carries the halogen atom is attached to one other alkyl group. In secondary haloalkanes, the carbon that carries the halogen atom has two C–C bonds, in tertiary haloalkanes, the carbon that carries the halogen atom has three C–C bonds. Haloalkanes can also be classified according to the type of halogen on group 7 responding to a specific halogenoalkane, haloalkanes containing carbon bonded to fluorine, chlorine, bromine, and iodine results in organofluorine, organochlorine, organobromine and organoiodine compounds, respectively. Compounds containing more than one kind of halogen are also possible, several classes of widely used haloalkanes are classified in this way chlorofluorocarbons, hydrochlorofluorocarbons and hydrofluorocarbons. These abbreviations are common in discussions of the environmental impact of haloalkanes. Haloalkanes generally resemble the parent alkanes in being colorless, relatively odorless and their boiling points are higher than the corresponding alkanes and scale with the atomic weight and number of halides
13.
1,1-Dichloroethane
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It is a colorless oily liquid with a chloroform-like odor. It is not easily soluble in water, but miscible with most organic solvents, large volumes of 1, 1-dichloroethane are manufactured, with annual production exceeding 1 million pounds in the United States. It is mainly used as a feedstock in chemical synthesis, chiefly of 1,1, 1-trichloroethane. It is also used as a solvent for plastics, oils and fats, as a degreaser, as a fumigant in insecticide sprays, in fire extinguishers. It is used in manufacturing of high-vacuum resistant rubber and for extraction of temperature-sensitive substances, thermal cracking at 400–500 °C and 10 MPa yields vinyl chloride. In the past,1, 1-dichloroethane was used as a surgical inhalational anesthetic, in the atmosphere,1, 1-dichloroethane decomposes with half-life of 62 days, chiefly by reaction of photolytically produced hydroxyl radicals. Dichloroethane and Dichloroethene on members. optushome. com. au ATSDR - Toxic Substances Portal CDC - NIOSH Pocket Guide to Chemical Hazards
14.
Ethyl iodide
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Ethyl iodide is a colorless, flammable chemical compound. It has the chemical formula C2H5I and is prepared by heating ethanol with iodine, on contact with air, especially on the effect of light, it decomposes and turns yellow or reddish from dissolved iodine. It may also be prepared by reaction between acid and ethanol distilling off the ethyl iodide. Ethyl iodide should be stored in copper powder to avoid fast decomposition, because iodide is a good leaving group, ethyl iodide is an excellent ethylating agent. It is also used as the hydrogen radical promoter, during the process the temperature is controlled. 3 C2 H5 O H + P I3 →3 C2 H5 I + H3 P O3 The crude product is purified by distillation
15.
Aluminium trichloride
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Aluminium chloride is the main compound of aluminium and chlorine. It is white, but samples are often contaminated with iron chloride, the solid has a low melting and boiling point. It is mainly produced and consumed in the production of aluminium metal, the compound is often cited as a Lewis acid. It is an example of a compound that cracks at mild temperature. AlCl3 adopts three different structures, depending on the temperature and the state, solid AlCl3 is a sheet-like layered cubic close packed layers. In this framework, the Al centres exhibit octahedral coordination geometry, in the melt, aluminium trichloride exists as the dimer Al2Cl6, with tetracoordinate aluminium. This change in structure is related to the density of the liquid phase vs solid aluminium trichloride. Al2Cl6 dimers are also found in the vapour phase, at higher temperatures, the Al2Cl6 dimers dissociate into trigonal planar AlCl3, which is structurally analogous to BF3. The melt conducts electricity poorly, unlike more ionic halides such as sodium chloride, the hexahydrate consists of octahedral 3+ centers and chloride counterions. Hydrogen bonds link the cation and anions, anhydrous aluminium chloride is a powerful Lewis acid, capable of forming Lewis acid-base adducts with even weak Lewis bases such as benzophenone and mesitylene. It forms tetrachloroaluminate AlCl4− in the presence of chloride ions, aluminium chloride reacts with calcium and magnesium hydrides in tetrahydrofuran forming tetrahydroaluminates. Aluminium chloride is hygroscopic, having a very pronounced affinity for water and it fumes in moist air and hisses when mixed with liquid water as the Cl− ions are displaced with H2O molecules in the lattice to form the hexahydrate Cl3. Such solutions are found to be acidic, indicative of partial hydrolysis of the Al3+ ion. 2 Al +3 Cl2 →2 AlCl32 Al +6 HCl →2 AlCl3 +3 H2 Aluminum chloride may be formed via a single displacement reaction between copper chloride and aluminum metal. 2 Al +3 CuCl2 →2 AlCl3 +3 Cu In the US in 1993, approximately 21,000 tons were produced, hydrated aluminium trichloride is prepared by dissolving aluminium oxides in hydrochloric acid. Metallic aluminum also readily dissolves in hydrochloric acid ─ releasing hydrogen gas, AlCl3 is probably the most commonly used Lewis acid and also one of the most powerful. It finds application in the industry as a catalyst for Friedel–Crafts reactions. Important products are detergents and ethylbenzene and it also finds use in polymerization and isomerization reactions of hydrocarbons
16.
Sodium bisulfate
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Sodium bisulfate, also known as sodium hydrogen sulfate, is the sodium salt of the bisulfate anion, with the molecular formula NaHSO4. Sodium bisulfate is a salt formed by partial neutralization of sulfuric acid by an equivalent of sodium base. It is a dry product that can be safely shipped and stored. Solutions of sodium bisulfate are acidic, with a 1M solution having a pH of around 1, one production method involves mixing stoichiometric quantities of sodium hydroxide and sulfuric acid which react to form sodium bisulfate and water. NaOH + H2SO4 → NaHSO4 + H2O A second production method involves reacting sodium chloride and sulfuric acid at elevated temperatures to produce sodium bisulfate, naCl + H2SO4 → NaHSO4 + HCl The liquid sodium bisulfate is sprayed and cooled so that it forms a solid bead. The hydrogen chloride gas is dissolved in water to produce hydrochloric acid as a useful coproduct of the reaction, there are only two producers in the USA, one being Jones-Hamilton Co. who uses the sulfuric acid/sodium chloride process, which produces the anhydrous form. The other supplier, Jost Chemical, uses the sodium hydroxide/sulfuric acid method, sodium bisulfate is used primarily to lower pH. For technical-grade applications, it is used in finishing, cleaning products. Sodium bisulfate is also AAFCO approved as a feed additive. It is used as a urine acidifier to reduce urinary stones in cats and it is highly toxic to at least some echinoderms, but fairly harmless to most other life forms, sodium bisulfate is used in controlling outbreaks of crown-of-thorns starfish. In jewelry making, sodium bisulfate is the primary ingredient used in many pickling solutions to remove the oxidation layer from surfaces, sodium bisulfate was the primary active ingredient in crystal toilet bowl cleaners Vanish and Sani-Flush, both now discontinued. Sodium bisulfate is the ingredient in some granular poultry litter treatments used to control ammonia. Sodium bisulfate is used as an additive to leaven cake mixes as well as being used in meat and poultry processing. Sodium bisulfate is considered generally recognized as safe by the FDA, the food-grade product also meets the requirements set out in the Food Chemicals Codex. It is denoted by E number E514ii in the EU and is approved for use in Australia, New Zealand, Canada. Where it is listed as additive 514, Food grade sodium bisulfate is used in a variety of food products, including beverages, dressings, sauces, and fillings. It has many synonyms including bisulfate of soda, sodium sulfate, mono sodium hydrogen sulfate, sodium hydrogen sulfate, sodium hydrosulfate
17.
Magnesium sulfate
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Magnesium sulfate is an inorganic salt containing magnesium, sulfur and oxygen, with the formula MgSO4. It is often encountered as the sulfate mineral epsomite, commonly called Epsom salt. The monohydrate, MgSO4·H2O is found as the mineral kieserite, the overall global annual usage in the mid-1970s of the monohydrate was 2.3 million tons, of which the majority was used in agriculture. Anhydrous magnesium sulfate is used as a drying agent, the anhydrous form is hygroscopic and is therefore difficult to weigh accurately, the hydrate is often preferred when preparing solutions. Epsom salt has been used as a component of bath salts. Epsom salt can also be used as a beauty product, athletes use it to soothe sore muscles, while gardeners use it to improve crops. It has a variety of uses, for example, Epsom salt is also effective in the removal of splinters. It is on the WHO Model List of Essential Medicines, the most important medications needed in a health system. Magnesium sulfate is a common mineral pharmaceutical preparation of magnesium, commonly known as Epsom salt, Magnesium sulfate is highly water-soluble and solubility is inhibited with lipids typically used in lotions. Lotions often employ the use of emulsions or suspensions to include oil and water-soluble ingredients. Temperature and concentration gradients may also be contributing factors to absorption, Epsom salt is used as bath salts and for isolation tanks. Magnesium sulfate is the preparation of intravenous magnesium. Internal uses include, Oral magnesium sulfate is used as a saline laxative or osmotic purgative. Replacement therapy for hypomagnesemia Magnesium sulfate is a agent for torsades de pointes in cardiac arrest under the ECC guidelines. As a bronchodilator after beta-agonist and anticholinergic agents have tried, e. g. in severe exacerbations of asthma. It is commonly administered via the route for the management of severe asthma attacks. Magnesium sulfate is effective in decreasing the risk that pre-eclampsia progresses to eclampsia, IV magnesium sulfate is used to prevent and treat seizures of eclampsia. It reduces the blood pressure but doesnt alter the diastolic blood pressure
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Hydrazone
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Hydrazones are a class of organic compounds with the structure R 1R 2C=NNH2. They are related to ketones and aldehydes by the replacement of the oxygen with the NNH2 functional group and they are formed usually by the action of hydrazine on ketones or aldehydes. The formation of aromatic hydrazone derivatives is used to measure the concentration of low molecular weight aldehydes and ketones, for example, dinitrophenylhydrazine coated onto a silica sorbent is the basis of an adsorption cartridge. The hydrazones are then eluted and analyzed by HPLC using a UV detector, the compound carbonyl cyanide-p-trifluoromethoxyphenylhydrazone is used to uncouple ATP synthesis and reduction of oxygen in oxidative phosphorylation in molecular biology. Phenylhydrazine reacts with glucose to form an osazone, hydrazone-based coupling methods are used in medical biotechnology to couple drugs to targeted antibodies, e. g. antibodies against a certain type of cancer cell. The hydrazone-based bond is stable at neutral pH, but is destroyed in the acidic environment of lysosomes of the cell. The drug is released in the cell, where it exerts its function. In aqueous solution, aliphatic hydrazones are 102- to 103-fold more sensitive to hydrolysis than analogous oximes, hydrazones are reactants in hydrazone iodination, the Shapiro reaction and the Bamford-Stevens reaction to vinyl compounds. A hydrazone is an intermediate in the Wolff–Kishner reduction, hydrazones can also be synthesized by the Japp–Klingemann reaction via β-keto-acids or β-keto-esters and aryl diazonium salts. The mechanochemical process was used recently as a one to synthesize pharmaceutically attractive phenol hydrazones. In N, N′-dialkylhydrazones the C=N bond can be hydrolysed, oxidised and reduced, the carbon atom if the C=N bond can react with organometallic nucleophiles. The alpha-hydrogen atom is more acidic by 10 orders of magnitude compared to the ketone, deprotonation with for instance LDA gives an azaenolate which can be alkylated by alkyl halides, a reaction pioneered by E. J. Corey and Dieter Enders in 1978, in asymmetric synthesis SAMP and RAMP are two chiral hydrazines that act as chiral auxiliary with a chiral hydrazone intermediate. Hydrazones Azo compound Imine Nitrosamine Hydrogenation of carbon–nitrogen double bonds
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Acetaldehyde
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Acetaldehyde is an organic chemical compound with the formula CH3CHO, sometimes abbreviated by chemists as MeCHO. It is one of the most important aldehydes, occurring widely in nature, Acetaldehyde occurs naturally in coffee, bread, and ripe fruit, and is produced by plants. It is also produced by the oxidation of ethanol by the liver enzyme alcohol dehydrogenase. Pathways of exposure include air, water, land, or groundwater, as well as drink, consumption of disulfiram inhibits acetaldehyde dehydrogenase, the enzyme responsible for the metabolism of acetaldehyde, thereby causing it to build up in the body. The International Agency for Research on Cancer has listed acetaldehyde as a Group 1 carcinogen, Acetaldehyde is one of the most frequently found air toxins with cancer risk greater than one in a million. In 1835, Liebig named it aldehyde, the name was altered to acetaldehyde. In 2003, global production was about 1 million tonnes, before 1962, ethanol and acetylene were the major sources of acetaldehyde. Since then, ethylene is the dominant feedstock, smaller quantities can be prepared by the partial oxidation of ethanol in an exothermic reaction. This process typically is conducted over a silver catalyst at about 500–650 °C, cH3CH2OH + 1⁄2 O2 → CH3CHO + H2O This method is one of the oldest routes for the industrial of preparation of acetaldehyde. Prior to the Wacker process and the availability of cheap ethylene and this reaction is catalyzed by mercury salts, C2H2 + Hg2+ + H2O → CH3CHO + Hg The mechanism involves the intermediacy of vinyl alcohol, which tautomerizes to acetaldehyde. The reaction is conducted at 90–95 °C, and the acetaldehyde formed is separated from water and mercury, in the wet oxidation process, iron sulfate is used to reoxidize the mercury back to the mercury salt. The resulting Iron sulfate is oxidized in a reactor with nitric acid. The process was once attractive because of the value of the hydrogen coproduct, the hydroformylation of methanol with catalysts like cobalt, nickel, or iron salts also produces acetaldehyde, although this process is of no industrial importance. Similarly noncompetitive, acetaldehyde arises from synthesis gas with modest selectivity, at room temperature, acetaldehyde is more stable than vinyl alcohol by 42.7 kJ/mol, Overall the keto-enol tautomerization occurs slowly but is catalyzed by acids. Photo-induced keto-enol tautomerization is viable under atmospheric or stratospheric conditions and this photo-tautomerization is relevant to the earths atmosphere, because vinyl alcohol is thought to be a precursor to carboxylic acids in the atmosphere. Acetaldehyde is an electrophile in organic synthesis. In condensation reactions, acetaldehyde is prochiral and it is used primarily as a source of the CH3C+H synthon in aldol and related condensation reactions. Grignard reagents and organolithium compounds react with MeCHO to give hydroxyethyl derivatives, in one of the more spectacular condensation reactions, three equivalents of formaldehyde add to MeCHO to give pentaerythritol, C4
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International Standard Book Number
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The International Standard Book Number is a unique numeric commercial book identifier. An ISBN is assigned to each edition and variation of a book, for example, an e-book, a paperback and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, the method of assigning an ISBN is nation-based and varies from country to country, often depending on how large the publishing industry is within a country. The initial ISBN configuration of recognition was generated in 1967 based upon the 9-digit Standard Book Numbering created in 1966, the 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108. Occasionally, a book may appear without a printed ISBN if it is printed privately or the author does not follow the usual ISBN procedure, however, this can be rectified later. Another identifier, the International Standard Serial Number, identifies periodical publications such as magazines, the ISBN configuration of recognition was generated in 1967 in the United Kingdom by David Whitaker and in 1968 in the US by Emery Koltay. The 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108, the United Kingdom continued to use the 9-digit SBN code until 1974. The ISO on-line facility only refers back to 1978, an SBN may be converted to an ISBN by prefixing the digit 0. For example, the edition of Mr. J. G. Reeder Returns, published by Hodder in 1965, has SBN340013818 -340 indicating the publisher,01381 their serial number. This can be converted to ISBN 0-340-01381-8, the check digit does not need to be re-calculated, since 1 January 2007, ISBNs have contained 13 digits, a format that is compatible with Bookland European Article Number EAN-13s. An ISBN is assigned to each edition and variation of a book, for example, an ebook, a paperback, and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, a 13-digit ISBN can be separated into its parts, and when this is done it is customary to separate the parts with hyphens or spaces. Separating the parts of a 10-digit ISBN is also done with either hyphens or spaces, figuring out how to correctly separate a given ISBN number is complicated, because most of the parts do not use a fixed number of digits. ISBN issuance is country-specific, in that ISBNs are issued by the ISBN registration agency that is responsible for country or territory regardless of the publication language. Some ISBN registration agencies are based in national libraries or within ministries of culture, in other cases, the ISBN registration service is provided by organisations such as bibliographic data providers that are not government funded. In Canada, ISBNs are issued at no cost with the purpose of encouraging Canadian culture. In the United Kingdom, United States, and some countries, where the service is provided by non-government-funded organisations. Australia, ISBNs are issued by the library services agency Thorpe-Bowker
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John Wiley & Sons
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Founded in 1807, Wiley is also known for publishing For Dummies. As of 2015, the company had 4,900 employees, Wiley was established in 1807 when Charles Wiley opened a print shop in Manhattan. Wiley later shifted its focus to scientific, technical, and engineering subject areas, Charles Wileys son John took over the business when his father died in 1826. The firm was successively named Wiley, Lane & Co. then Wiley & Putnam, the company acquired its present name in 1876, when Johns second son William H. Wiley joined his brother Charles in the business. Through the 20th century, the company expanded its activities, the sciences. Since the establishment of the Nobel Prize in 1901, Wiley and its companies have published the works of more than 450 Nobel Laureates. Wiley in December 2010 opened an office in Dubai, to build on its business in the Middle East more effectively, the company has had an office in Beijing, China, since 2001, and China is now its sixth-largest market for STEM content. Wiley established publishing operations in India in 2006, and has established a presence in North Africa through sales contracts with academic institutions in Tunisia, Libya, and Egypt. On April 16,2012, the announced the establishment of Wiley Brasil Editora LTDA in São Paulo, Brazil. Wileys scientific, technical, and medical business was expanded by the acquisition of Blackwell Publishing in February 2007. Through a backfile initiative completed in 2007,8.2 million pages of content have been made available online. Other major journals published include Angewandte Chemie, Advanced Materials, Hepatology, International Finance, launched commercially in 1999, Wiley InterScience provided online access to Wiley journals, major reference works, and books, including backfile content. Journals previously from Blackwell Publishing were available online from Blackwell Synergy until they were integrated into Wiley InterScience on June 30,2008, in December 2007, Wiley also began distributing its technical titles through the Safari Books Online e-reference service. On February 17,2012, Wiley announced the acquisition of Inscape Holdings Inc. which provides DISC assessments and training for interpersonal business skills. On August 13,2012, Wiley announced it entered into an agreement to sell all of its travel assets, including all of its interests in the Frommers brand. On October 2,2012, Wiley announced it would acquire Deltak edu, LLC, Deltak is expected to contribute solid growth to both Wileys Global Education business and Wiley overall. Seventh-generation members Jesse and Nate Wiley work in the companys Professional/Trade and Scientific, Technical, Medical, and Scholarly businesses, respectively. Wiley has been owned since 1962, and listed on the New York Stock Exchange since 1995, its stock is traded under the symbols NYSE, JW. A and NYSE
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Halocarbon
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Chlorine halocarbons are the most common and are called organochlorides. Many synthetic organic compounds such as polymers, and a few natural ones, contain halogen atoms. Organochlorides are the most common industrially used organohalides, although the other organohalides are used commonly in organic synthesis, except for extremely rare cases, organohalides are not produced biologically, but many pharmaceuticals are organohalides. Notably, many such as Prozac have trifluoromethyl groups. For information on inorganic chemistry, see halide. Halocarbons are typically classified in the ways as the similarly structured organic compounds that have hydrogen atoms occupying the molecular sites of the halogen atoms in halocarbons. The halogen atoms in molecules are often called substituents, as though those atoms had been substituted for hydrogen atoms. However halocarbons are prepared in ways that do not involve direct substitution of halogens for hydrogens. A few halocarbons are produced in massive amounts by microorganisms, for example, several million tons of methyl bromide are estimated to be produced by marine organisms annually. Most of the halocarbons encountered in everyday life – solvents, medicines, the first synthesis of halocarbons was achieved in the early 1800s. Production began accelerating when their useful properties as solvents and anesthetics were discovered, development of plastics and synthetic elastomers has led to greatly expanded scale of production. A substantial percentage of drugs are halocarbons, a large amount of the naturally occurring halocarbons are created by wood fire, dioxine for example, or volcanic activities. A second large source are marine algae which produce several chlorinated methane and ethane containing compounds, there are several thousand complex halocarbons known, produced mainly by marine species. Although chlorine compounds are the majority of the compounds, bromides, iodides and fluorides have also been found. These three representatives, thyroxine from humans, tyrian purple from snails and fluoroacetate from plants, also show that unrelated species use halocarbons for several purposes, organoiodine compounds, called organic iodides, are similar in structure to organochlorine and organobromine compounds, but the C-I bond is weaker. Many organic iodides are known, but few are of industrial importance. Iodide compounds are produced as nutritional supplements. The thyroxin hormones are essential for health, hence the usefulness of iodized salt
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