|
Lajos Winkler
Lajos Winkler (May 21, 1863 – April 14, 1939) was a Hungary, Hungarian analytical chemist. He is best known today for his discovery of the Winkler method for the measurement of oxygen dissolved in water. Life Relatively little is in print in English concerning the life of Lajos Winkler. Winkler studied science at the University of Budapest, Budapest University of Science, receiving his doctorate there in 1890, while working with Carl von Than. He stayed on to work as a lecturer, among other positions, and directed the Institute of Chemistry, starting in 1909, for more than 25 years. He is said to have published several hundred papers, to have helped found the ''Hungarian Journal of Chemistry'', and to have been a member of the Hungarian Academy of Sciences. See also the study of Vamos for more information and references. Dissolved oxygen Natural water contains molecular oxygen (O2), necessary for life in ponds, rivers, and so on. A common nineteenth-century test fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Budapest
A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. Universities typically offer both undergraduate and postgraduate programs. In the United States, the designation is reserved for colleges that have a graduate school. The word ''university'' is derived from the Latin ''universitas magistrorum et scholarium'', which roughly means "community of teachers and scholars". The first universities were created in Europe by Catholic Church monks. The University of Bologna (''Università di Bologna''), founded in 1088, is the first university in the sense of: *Being a high degree-awarding institute. *Having independence from the ecclesiastic schools, although conducted by both clergy and non-clergy. *Using the word ''universitas'' (which was coined at its foundation). *Issuing secular and non-secular degrees: grammar, rhetoric, logic, theology, canon law, notarial law.Hunt Janin: "The university i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Von Than
Károly Antal Than de Apát – also called as Carl von Than – (20 December 1834 – 5 July 1908) was a Hungarian chemist who discovered carbonyl sulfide in 1867. Life AKároly Than was born in Óbecse, Kingdom of Hungary, Austrian Empire (today Bečej, Serbia). His mother was Otillia Setényi. He interrupted his education and joined the Hungarian army in the war of independence 1848 at the age of 14. On his return, he found his mother dead and his father ruined. Than worked in several pharmacies to earn money form completing his education. After attending a school in Szeged, Than started to study medicine and later chemistry at the University of Vienna. He received his PhD for work with Josef Redtenbacher in 1858. After working for some time as assistant of Redtenbacher, he left to study with Robert Bunsen at the University of Heidelberg and with Charles-Adolphe Wurtz at the University of Paris. On his return to Redtenbacher in 1859, he worked as lecturer at the University of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hungary
Hungary ( hu, Magyarország ) is a landlocked country in Central Europe. Spanning of the Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the south, Croatia and Slovenia to the southwest, and Austria to the west. Hungary has a population of nearly 9 million, mostly ethnic Hungarians and a significant Romani minority. Hungarian, the official language, is the world's most widely spoken Uralic language and among the few non-Indo-European languages widely spoken in Europe. Budapest is the country's capital and largest city; other major urban areas include Debrecen, Szeged, Miskolc, Pécs, and Győr. The territory of present-day Hungary has for centuries been a crossroads for various peoples, including Celts, Romans, Germanic tribes, Huns, West Slavs and the Avars. The foundation of the Hungarian state was established in the late 9th century AD with the conquest of the Carpathian Basin by Hungar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Analytical Chemist
Analytical chemistry studies and uses instruments and methods to separate, identify, and quantify matter. In practice, separation, identification or quantification may constitute the entire analysis or be combined with another method. Separation isolates analytes. Qualitative analysis identifies analytes, while quantitative analysis determines the numerical amount or concentration. Analytical chemistry consists of classical, wet chemical methods and modern, instrumental methods. Classical qualitative methods use separations such as precipitation, extraction, and distillation. Identification may be based on differences in color, odor, melting point, boiling point, solubility, radioactivity or reactivity. Classical quantitative analysis uses mass or volume changes to quantify amount. Instrumental methods may be used to separate samples using chromatography, electrophoresis or field flow fractionation. Then qualitative and quantitative analysis can be performed, often with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winkler Method
The Winkler test is used to determine the concentration of dissolved oxygen in water samples. Dissolved oxygen (D.O.) is widely used in water quality studies and routine operation of water reclamation facilities to analyze its level of oxygen saturation. In the test, an excess of manganese(II) salt, iodide (I−) and hydroxide (OH−) ions are added to a water sample causing a white precipitate of Mn(OH)2 to form. This precipitate is then oxidized by the oxygen that is present in the water sample into a brown manganese-containing precipitate with manganese in a more highly oxidized state (either Mn(III) or Mn(IV)). In the next step, a strong acid (either hydrochloric acid or sulfuric acid) is added to acidify the solution. The brown precipitate then converts the iodide ion (I−) to iodine. The amount of dissolved oxygen is directly proportional to the titration of iodine with a thiosulfate solution. Today, the method is effectively used as its colorimetric modification, where t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. Oxygen is Earth's most abundant element, and after hydrogen and helium, it is the third-most abundant element in the universe. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula . Diatomic oxygen gas currently constitutes 20.95% of the Earth's atmosphere, though this has changed considerably over long periods of time. Oxygen makes up almost half of the Earth's crust in the form of oxides.Atkins, P.; Jones, L.; Laverman, L. (2016).''Chemical Principles'', 7th edition. Freeman. Many major classes of organic molecules in living organisms contain oxygen atoms, such as proteins, nucleic acids, carbohydrates, and fats, as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hungarian Academy Of Sciences
The Hungarian Academy of Sciences ( hu, Magyar Tudományos Akadémia, MTA) is the most important and prestigious learned society of Hungary. Its seat is at the bank of the Danube in Budapest, between Széchenyi rakpart and Akadémia utca. Its main responsibilities are the cultivation of science, dissemination of scientific findings, supporting research and development, and representing Hungarian science domestically and around the world. History The history of the academy began in 1825 when Count István Széchenyi offered one year's income of his estate for the purposes of a ''Learned Society'' at a district session of the Diet in Pressburg (Pozsony, present Bratislava, seat of the Hungarian Parliament at the time), and his example was followed by other delegates. Its task was specified as the development of the Hungarian language and the study and propagation of the sciences and the arts in Hungarian. It received its current name in 1845. Its central building was inaugurate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Alfred Wanklyn
Prof James Alfred Wanklyn FRSE FCS MRCS (18 February 1834 – 19 July 1906) was a nineteenth-century English analytical chemist who is remembered today chiefly for his "ammonia method" of determining water quality and for his fierce arguments with those, such as Edward Frankland, who opposed him over matters related to water analysis. He worked with Edward Frankland and Lyon Playfair. He gives his name to the Wanklyn reaction. Life He was born in Ashton-under-Lyne on 18 February 1834 the son of Thomas Wanklyn and his wife, Ann Dakeyne, both members of the Moravian Brethren. He was educated at the Moravian School in Fairfield, Lancashire. He was at first apprenticed to a physician in Manchester 1843 to 1848. This seemed to inspire an interest in drugs and human health. He then went to study Chemistry at Owen's College in Manchester. He then did postgraduate studies at Heidelberg under Robert Bunsen in Germany 1857 to 1859.ODNB: Wanklyn In 1859 he moved to Edinburgh and be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winkler Test For Dissolved Oxygen
The Winkler test is used to determine the concentration of dissolved oxygen in water samples. Dissolved oxygen (D.O.) is widely used in water quality studies and routine operation of water reclamation facilities to analyze its level of oxygen saturation. In the test, an excess of manganese(II) salt, iodide (I−) and hydroxide (OH−) ions are added to a water sample causing a white precipitate of Mn(OH)2 to form. This precipitate is then oxidized by the oxygen that is present in the water sample into a brown manganese-containing precipitate with manganese in a more highly oxidized state (either Mn(III) or Mn(IV)). In the next step, a strong acid (either hydrochloric acid or sulfuric acid) is added to acidify the solution. The brown precipitate then converts the iodide ion (I−) to iodine. The amount of dissolved oxygen is directly proportional to the titration of iodine with a thiosulfate solution. Today, the method is effectively used as its colorimetric modification, where t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manganese(II) Hydroxide
Manganese(II) hydroxide is the inorganic compound with the formula Mn (OH)2. It is a white solid although samples darken quickly upon exposure to air owing to oxidation. It is poorly soluble in water. Preparation and reactions Manganese(II) hydroxide precipitates as a solid when an alkali metal hydroxide is added to an aqueous solution of Mn2+ salt:H. Lux "Manganese(IV) Hydroxide" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 1456. :Mn2+ + 2 NaOH → Mn(OH)2 + 2 Na+ Manganese(II) hydroxide oxidises readily in air, as indicated by darkening of samples. The compound adopts the brucite Brucite is the mineral form of magnesium hydroxide, with the chemical formula Mg( OH)2. It is a common alteration product of periclase in marble; a low-temperature hydrothermal vein mineral in metamorphosed limestones and chlorite schists; and ... structure, as do several other metal dihydroxides. References {{Hydr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titration
Titration (also known as titrimetry and volumetric analysis) is a common laboratory method of quantitative 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 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, the French chemist Joseph Louis Gay-Lussac first used ''titre'' as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winkler Bottle
The Winkler test is used to determine the concentration of dissolved oxygen in water samples. Dissolved oxygen (D.O.) is widely used in water quality studies and routine operation of water reclamation facilities to analyze its level of oxygen saturation. In the test, an excess of manganese(II) salt, iodide (I−) and hydroxide (OH−) ions are added to a water sample causing a white precipitate of Mn(OH)2 to form. This precipitate is then oxidized by the oxygen that is present in the water sample into a brown manganese-containing precipitate with manganese in a more highly oxidized state (either Mn(III) or Mn(IV)). In the next step, a strong acid (either hydrochloric acid or sulfuric acid) is added to acidify the solution. The brown precipitate then converts the iodide ion (I−) to iodine. The amount of dissolved oxygen is directly proportional to the titration of iodine with a thiosulfate solution. Today, the method is effectively used as its colorimetric modification, wher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_-_09.JPG "Click for more on -> University Of Budapest")
