Germany the Federal Republic of Germany, is a country in Central and Western Europe, lying between the Baltic and North Seas to the north, the Alps to the south. It borders Denmark to the north and the Czech Republic to the east and Switzerland to the south, France to the southwest, Luxembourg and the Netherlands to the west. Germany includes 16 constituent states, covers an area of 357,386 square kilometres, has a temperate seasonal climate. With 83 million inhabitants, it is the second most populous state of Europe after Russia, the most populous state lying in Europe, as well as the most populous member state of the European Union. Germany is a decentralized country, its capital and largest metropolis is Berlin, while Frankfurt serves as its financial capital and has the country's busiest airport. Germany's largest urban area is the Ruhr, with its main centres of Essen; the country's other major cities are Hamburg, Cologne, Stuttgart, Düsseldorf, Dresden, Bremen and Nuremberg. Various Germanic tribes have inhabited the northern parts of modern Germany since classical antiquity.
A region named Germania was documented before 100 AD. During the Migration Period, the Germanic tribes expanded southward. Beginning in the 10th century, German territories formed a central part of the Holy Roman Empire. During the 16th century, northern German regions became the centre of the Protestant Reformation. After the collapse of the Holy Roman Empire, the German Confederation was formed in 1815; the German revolutions of 1848–49 resulted in the Frankfurt Parliament establishing major democratic rights. In 1871, Germany became a nation state when most of the German states unified into the Prussian-dominated German Empire. After World War I and the revolution of 1918–19, the Empire was replaced by the parliamentary Weimar Republic; the Nazi seizure of power in 1933 led to the establishment of a dictatorship, the annexation of Austria, World War II, the Holocaust. After the end of World War II in Europe and a period of Allied occupation, Austria was re-established as an independent country and two new German states were founded: West Germany, formed from the American and French occupation zones, East Germany, formed from the Soviet occupation zone.
Following the Revolutions of 1989 that ended communist rule in Central and Eastern Europe, the country was reunified on 3 October 1990. Today, the sovereign state of Germany is a federal parliamentary republic led by a chancellor, it is a great power with a strong economy. As a global leader in several industrial and technological sectors, it is both the world's third-largest exporter and importer of goods; as a developed country with a high standard of living, it upholds a social security and universal health care system, environmental protection, a tuition-free university education. The Federal Republic of Germany was a founding member of the European Economic Community in 1957 and the European Union in 1993, it is part of the Schengen Area and became a co-founder of the Eurozone in 1999. Germany is a member of the United Nations, NATO, the G7, the G20, the OECD. Known for its rich cultural history, Germany has been continuously the home of influential and successful artists, musicians, film people, entrepreneurs, scientists and inventors.
Germany has a large number of World Heritage sites and is among the top tourism destinations in the world. The English word Germany derives from the Latin Germania, which came into use after Julius Caesar adopted it for the peoples east of the Rhine; the German term Deutschland diutisciu land is derived from deutsch, descended from Old High German diutisc "popular" used to distinguish the language of the common people from Latin and its Romance descendants. This in turn descends from Proto-Germanic *þiudiskaz "popular", derived from *þeudō, descended from Proto-Indo-European *tewtéh₂- "people", from which the word Teutons originates; the discovery of the Mauer 1 mandible shows that ancient humans were present in Germany at least 600,000 years ago. The oldest complete hunting weapons found anywhere in the world were discovered in a coal mine in Schöningen between 1994 and 1998 where eight 380,000-year-old wooden javelins of 1.82 to 2.25 m length were unearthed. The Neander Valley was the location where the first non-modern human fossil was discovered.
The Neanderthal 1 fossils are known to be 40,000 years old. Evidence of modern humans dated, has been found in caves in the Swabian Jura near Ulm; the finds included 42,000-year-old bird bone and mammoth ivory flutes which are the oldest musical instruments found, the 40,000-year-old Ice Age Lion Man, the oldest uncontested figurative art discovered, the 35,000-year-old Venus of Hohle Fels, the oldest uncontested human figurative art discovered. The Nebra sky disk is a bronze artefact created during the European Bronze Age attributed to a site near Nebra, Saxony-Anhalt, it is part of UNESCO's Memory of the World Programme. The Germanic tribes are thought to date from the Pre-Roman Iron Age. From southern Scandinavia and north Germany, they expanded south and west from the 1st century BC, coming into contact with the Celtic tribes of Gaul as well
Piperine, along with its isomer chavicine, is the alkaloid responsible for the pungency of black pepper and long pepper. It has been used in some forms of traditional medicine. Piperine is extracted from black pepper using dichloromethane. Aqueous hydrotropes can be used in the extraction to result in high selectivity; the amount of piperine varies from 1–2% in long pepper, to 5–10% in commercial white and black peppers. Further, it may be prepared by treating the solvent-free residue from an alcoholic extract of black pepper, with a solution of potassium hydroxide to remove resin and solution of the washed, insoluble residue in warm alcohol, from which the alkaloid crystallises on cooling. Piperine yields salts only with strong acids; the platinichloride B4·H2PtCl6 forms orange-red needles. Iodine in potassium iodide added to an alcoholic solution of the base in the presence of a little hydrochloric acid gives a characteristic periodide, B2·HI·I2, crystallising in steel-blue needles, melting point 145 °C.
Piperine was discovered in 1819 by Hans Christian Ørsted, who isolated it from the fruits of Piper nigrum, the source plant of both black and white pepper. Piperine was found in Piper longum and Piper officinarum C. DC. two species called "long pepper". A component of pungency by piperine results from activation of the heat- and acidity-sensing TRPV ion channels, TRPV1 and TRPA1, on nociceptors, the pain-sensing nerve cells. Piperine is under preliminary research for its potential to affect bioavailability of other compounds in food and dietary supplements, such as a possible effect on the bioavailability of curcumin. Piperidine, a cyclic six-membered amine that results from hydrolysis of piperine Capsaicin, the active piquant chemical in chili peppers Allyl isothiocyanate, the active piquant chemical in mustard, radishes and wasabi Allicin, the active piquant flavor chemical in raw garlic and onions Ilepcimide Piperlongumine
Lactones are cyclic carboxylic esters, containing a 1-oxacycloalkan-2-one structure, or analogues having unsaturation or heteroatoms replacing one or more carbon atoms of the ring. Lactones are formed by intramolecular esterification of the corresponding hydroxycarboxylic acids, which takes place spontaneously when the ring, formed is five- or six-membered. Lactones with three- or four-membered rings are reactive, making their isolation difficult. Special methods are required for the laboratory synthesis of small-ring lactones as well as those that contain rings larger than six-membered. Lactones are named according to the precursor acid molecule, with a -lactone suffix and a Greek letter prefix that specifies the number of carbon atoms in the heterocycle — that is, the distance between the relevant -OH and the -COOH groups along said backbone; the first carbon atom after the carbon in the -COOH group on the parent compound is labelled α, the second will be labeled β, so forth. Therefore, the prefixes indicate the size of the lactone ring: α-lactone = 3-membered ring, β-lactone = 4-membered, γ-lactone = 5-membered, etc.
The other suffix used to denote a lactone is -olide, used in substance class names like butenolide, cardenolide or bufadienolide. To obtain the preferred IUPAC names, lactones are named as heterocyclic pseudoketones by adding the suffix ‘one’, ‘dione’, ‘thione’, etc. and the appropriate multiplicative prefixes to the name of the heterocyclic parent hydride. The name lactone derives from the ring compound called lactide, formed from the dehydration of 2-hydroxypropanoic acid CH3-CH-COOH. Lactic acid, in turn, derives its name from its original isolation from soured milk. An internal dehydration within the same molecule of lactic acid would have produced alpha-propiolactone, a lactone with a 3-membered ring. Occurring lactones are saturated and unsaturated γ- and δ-lactones, to a lesser extent macrocyclic lactones; the γ- and δ-lactones are intramolecular esters of the corresponding hydroxy fatty acids. They contribute to the aroma of fruits, butter and other foods. Cyclopentadecanolide is responsible for the musklike odor of angelica root oil.
Of the occurring bicyclic lactones, phthalides are responsible for the odors of celery and lovage oils, coumarin for woodruff. Lactone rings occur as building blocks in nature, such as in ascorbic acid, nepetalactone, hormones, neurotransmitters, anticancer drugs, phytoestrogens. Many methods in ester synthesis can be applied to that of lactones. In one industrial synthesis of oxandrolone the key lactone-forming step is an organic reduction - esterification. In halolactonization, an alkene is attacked by a halogen via electrophilic addition with the cationic intermediate captured intramolecularly by an adjacent carboxylic acid. Specific methods include Yamaguchi esterification, Shiina macrolactonization, Baeyer–Villiger oxidation and nucleophilic abstraction; the γ-lactones γ-octalactone, γ-nonalactone, γ-decalactone, γ-undecalactone can be prepared in good yield in a one-step process by radical addition of primary fatty alcohols to acrylic acid, using di-tert-butyl peroxide as a catalyst. The most stable structure for lactones are the 5-membered γ-lactones and 6-membered δ-lactones because, as in all organic cycles, 5 and 6 membered rings minimize the strain of bond angles.
Γ-lactones are so stable that, in the presence of dilute acids at room temperature, 4-hydroxy acids undergo spontaneous esterification and cyclisation to the lactone. Β-lactones can only be made by special methods. Α-lactones can be detected as transient species in mass spectrometry experiments. The reactions of lactones are similar to those of esters, as exemplified by gamma-lactone in the following sections: Heating a lactone with a base will hydrolyse the lactone to its parent compound, the straight chained bifunctional compound. Like straight-chained esters, the hydrolysis-condensation reaction of lactones is a reversible reaction, with an equilibrium. However, the equilibrium constant of the hydrolysis reaction of the lactone is lower than that of the straight-chained ester i.e. the products are less favored in the case of the lactones. This is because although the enthalpies of the hydrolysis of esters and lactones are about the same, the entropy of the hydrolysis of lactones is less than the entropy of straight-chained esters.
Straight-chained esters give two products upon hydrolysis, making the entropy change more favorable than in the case of lactones which gives only a single product. Lactones can be reduced to diols using lithium aluminium hydride in dry ether; the reduction reaction will first break the ester bond of the lactone, reduce the aldehyde group to the alcohol group. For instance, gamma-lactones will be reduced to butane-1,4-diol, (CH2-2-CH2. Lactones react with ethanolic ammonia, which will first break the ester bond and react with the acidic -COOH group, because of the basic properties of ammonia, to form a difunctional group, i.e. alcohol and amide. Gamma-lactones will react to yield CH2-2-CO-NH2. Lactones form polyesters according to the formula: Sesquiterpene lactones, found in many plants, can react with other molecules via a Michael reaction. Lactones contribute sig
Sulfuric acid known as vitriol, is a mineral acid composed of the elements sulfur and hydrogen, with molecular formula H2SO4. It is a colorless and syrupy liquid, soluble in water, in a reaction, exothermic, its corrosiveness can be ascribed to its strong acidic nature, and, if at a high concentration, its dehydrating and oxidizing properties. It is hygroscopic absorbing water vapor from the air. Upon contact, sulfuric acid can cause severe chemical burns and secondary thermal burns. Sulfuric acid is a important commodity chemical, a nation's sulfuric acid production is a good indicator of its industrial strength, it is produced with different methods, such as contact process, wet sulfuric acid process, lead chamber process and some other methods. Sulfuric acid is a key substance in the chemical industry, it is most used in fertilizer manufacture, but is important in mineral processing, oil refining, wastewater processing, chemical synthesis. It has a wide range of end applications including in domestic acidic drain cleaners, as an electrolyte in lead-acid batteries, in various cleaning agents.
Although nearly 100% sulfuric acid can be made, the subsequent loss of SO3 at the boiling point brings the concentration to 98.3% acid. The 98.3% grade is more stable in storage, is the usual form of what is described as "concentrated sulfuric acid". Other concentrations are used for different purposes; some common concentrations are: "Chamber acid" and "tower acid" were the two concentrations of sulfuric acid produced by the lead chamber process, chamber acid being the acid produced in the lead chamber itself and tower acid being the acid recovered from the bottom of the Glover tower. They are now obsolete as commercial concentrations of sulfuric acid, although they may be prepared in the laboratory from concentrated sulfuric acid if needed. In particular, "10M" sulfuric acid is prepared by adding 98% sulfuric acid to an equal volume of water, with good stirring: the temperature of the mixture can rise to 80 °C or higher. Sulfuric acid reacts with its anhydride, SO3, to form H2S2O7, called pyrosulfuric acid, fuming sulfuric acid, Disulfuric acid or oleum or, less Nordhausen acid.
Concentrations of oleum are either expressed in terms of % SO3 or as % H2SO4. Pure H2S2O7 is a solid with melting point of 36 °C. Pure sulfuric acid has a vapor pressure of <0.001 mmHg at 25 °C and 1 mmHg at 145.8 °C, 98% sulfuric acid has a <1 mmHg vapor pressure at 40 °C. Pure sulfuric acid is a viscous clear liquid, like oil, this explains the old name of the acid. Commercial sulfuric acid is sold in several different purity grades. Technical grade H2SO4 is impure and colored, but is suitable for making fertilizer. Pure grades, such as United States Pharmacopeia grade, are used for making pharmaceuticals and dyestuffs. Analytical grades are available. Nine hydrates are known, but four of them were confirmed to be tetrahydrate and octahydrate. Anhydrous H2SO4 is a polar liquid, having a dielectric constant of around 100, it has a high electrical conductivity, caused by dissociation through protonating itself, a process known as autoprotolysis. 2 H2SO4 ⇌ H3SO+4 + HSO−4The equilibrium constant for the autoprotolysis is Kap = = 2.7×10−4The comparable equilibrium constant for water, Kw is 10−14, a factor of 1010 smaller.
In spite of the viscosity of the acid, the effective conductivities of the H3SO+4 and HSO−4 ions are high due to an intramolecular proton-switch mechanism, making sulfuric acid a good conductor of electricity. It is an excellent solvent for many reactions; because the hydration reaction of sulfuric acid is exothermic, dilution should always be performed by adding the acid to the water rather than the water to the acid. Because the reaction is in an equilibrium that favors the rapid protonation of water, addition of acid to the water ensures that the acid is the limiting reagent; this reaction is best thought of as the formation of hydronium ions: H2SO4 + H2O → H3O+ + HSO−4 Ka1 = 2.4×106 HSO−4 + H2O → H3O+ + SO2−4 Ka2 = 1.0×10−2 HSO−4 is the bisulfate anion and SO2−4 is the sulfate anion. Ka1 and Ka2 are the acid dissociation constants; because the hydration of sulfuric acid is thermodynamically favorable and the affinity of it for water is sufficiently strong, sulfuric acid is an excellent dehydrating agent.
Concentrated sulfuric acid has a powerful dehydrating property, removing water from other chemical compounds including sugar and other carbohydrates and producing carbon and steam. In the laboratory, this is demonstrated by mixing table sugar into sulfuric acid; the sugar changes from white to dark brown and to black as carbon is formed. A rigid column of black, porous carbon will emerge as well; the carbon will smell of caramel due to the heat generated. C 12 H 22 O 11 ⏞ sucrose → H 2 SO 4 12 C + 11 H 2
The Davy Medal is awarded by the Royal Society of London "for an outstandingly important recent discovery in any branch of chemistry". Named after Humphry Davy, the medal is awarded with a monetary gift of £1000; the medal was first awarded in 1877 to Robert Wilhelm Bunsen and Gustav Robert Kirchhoff "for their researches & discoveries in spectrum analysis", has since been awarded 140 times. The medal is awarded annually, unlike other Royal Society medals, such as the Hughes Medal, it has been awarded annually without missing a year; the medal has been awarded to multiple individuals in the same year: in 1882 it was awarded to Dmitri Mendeleev and Julius Lothar Meyer "for their discovery of the periodic relations of the atomic weights". Source: Royal Society General"Davy Medal". Royal Society. Retrieved 2014-06-15. Specific Royal Society official website
Heinrich Limpricht was a German chemist. Limpricht was a pupil of Friedrich Wöhler. In 1852 he in 1855 extraordinary professor at the University of Göttingen. In 1860, he became ordinary professor at the Institute for Organic Chemistry at the University of Greifswald, his oldest daughter Marie married in 1875 to Protestant theologian Julius Wellhausen. Rudolph Fittig and Hans von Pechmann were two of Limpricht's notable pupils. Karl von Auwers. "Heinrich Limpricht". Chem. Ber. 42: 5001–5036. Doi:10.1002/cber.190904204121. Gerda Schneider: Heinrich Limpricht und sein Schülerkreis. Greifswald 1970 Genealogy database entry by Gregory S. Girolami 1998 H. Limpricht. "Untersuchungen über die Schleimsäure und Pyroschleimsäure". Justus Liebigs Annalen der Chemie und Pharmacie. 165: 253–302. Doi:10.1002/jlac.18731650207
In organic chemistry, a hydrocarbon is an organic compound consisting of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons from which one hydrogen atom has been removed are functional groups called hydrocarbyls; because carbon has 4 electrons in its outermost shell carbon has four bonds to make, is only stable if all 4 of these bonds are used. Aromatic hydrocarbons, alkanes and alkyne-based compounds are different types of hydrocarbons. Most hydrocarbons found on Earth occur in crude oil, where decomposed organic matter provides an abundance of carbon and hydrogen which, when bonded, can catenate to form limitless chains; as defined by IUPAC nomenclature of organic chemistry, the classifications for hydrocarbons are: Saturated hydrocarbons are the simplest of the hydrocarbon species. They are composed of single bonds and are saturated with hydrogen; the formula for acyclic saturated hydrocarbons is CnH2n+2. The most general form of saturated hydrocarbons is CnH2n +2.
Those with one ring are the cycloalkanes. Saturated hydrocarbons are the basis of petroleum fuels and are found as either linear or branched species. Substitution reaction is their characteristics property. Hydrocarbons with the same molecular formula but different structural formulae are called structural isomers; as given in the example of 3-methylhexane and its higher homologues, branched hydrocarbons can be chiral. Chiral saturated hydrocarbons constitute the side chains of biomolecules such as chlorophyll and tocopherol. Unsaturated hydrocarbons have one or more triple bonds between carbon atoms; those with double bond are called alkenes. Those with one double bond have the formula CnH2n; those containing triple bonds are called alkyne. Those with one triple bond have the formula CnH2n−2. Aromatic hydrocarbons known as arenes, are hydrocarbons that have at least one aromatic ring. Hydrocarbons can be gases, waxes or low melting solids or polymers; because of differences in molecular structure, the empirical formula remains different between hydrocarbons.
This inherent ability of hydrocarbons to bond to themselves is known as catenation, allows hydrocarbons to form more complex molecules, such as cyclohexane, in rarer cases, arenes such as benzene. This ability comes from the fact that the bond character between carbon atoms is non-polar, in that the distribution of electrons between the two elements is somewhat due to the same electronegativity values of the elements, does not result in the formation of an electrophile. With catenation comes the loss of the total amount of bonded hydrocarbons and an increase in the amount of energy required for bond cleavage due to strain exerted upon the molecule. In simple chemistry, as per valence bond theory, the carbon atom must follow the 4-hydrogen rule, which states that the maximum number of atoms available to bond with carbon is equal to the number of electrons that are attracted into the outer shell of carbon. In terms of shells, carbon consists of an incomplete outer shell, which comprises 4 electrons, thus has 4 electrons available for covalent or dative bonding.
Hydrocarbons are hydrophobic like lipids. Some hydrocarbons are abundant in the solar system. Lakes of liquid methane and ethane have been found on Titan, Saturn's largest moon, confirmed by the Cassini-Huygens Mission. Hydrocarbons are abundant in nebulae forming polycyclic aromatic hydrocarbon compounds. Hydrocarbons are a primary energy source for current civilizations; the predominant use of hydrocarbons is as a combustible fuel source. In their solid form, hydrocarbons take the form of asphalt. Mixtures of volatile hydrocarbons are now used in preference to the chlorofluorocarbons as a propellant for aerosol sprays, due to chlorofluorocarbons' impact on the ozone layer. Methane and ethane are gaseous at ambient temperatures and cannot be liquefied by pressure alone. Propane is however liquefied, exists in'propane bottles' as a liquid. Butane is so liquefied that it provides a safe, volatile fuel for small pocket lighters. Pentane is a colorless liquid at room temperature used in chemistry and industry as a powerful nearly odorless solvent of waxes and high molecular weight organic compounds, including greases.
Hexane is a used non-polar, non-aromatic solvent, as well as a significant fraction of common gasoline. The C6 through C10 alkanes and isomeric cycloalkanes are the top components of gasoline, jet fuel and specialized industrial solvent mixtures. With the progressive addition of carbon units, the simple non-ring structured hydrocarbons have higher viscosities, lubricating indices, boiling points, solidification temperatures, deeper color. At the opposite extreme from methane lie the heavy tars that remain as the lowest fraction in a crude oil refining retort, they are collected and utilized as roofing comp