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Conductometry
Conductometry is a measurement of electrolytic conductivity to monitor a progress of chemical reaction. Conductometry has notable application in analytical chemistry, where conductometric titration is a standard technique. In usual analytical chemistry practice, the term ''conductometry'' is used as a synonym of ''conductometric titration while the term conductimetry is used to describe non-titrative applications.Khopkar, S.M., "Basic Concepts of Analytical Chemistry", 3rd edition, 2007, . Conductometry is often applied to determine the total conductance of a solution or to analyze the end point of titrations that include ions.Braun, R.D., "Chemical Analysis". Encyclopædia Britannica. Encyclopædia Britannica Online. Encyclopædia Britannica Inc., 2015, Web. 07 Dec. 2015. History Conductive measurements began as early as the 18th century, when Andreas Baumgartner noticed that salt and mineral waters from Bad Gastein in Austria conducted electricity.Lubert, K. and K. Kalcher, "His ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conductivity (electrolytic)
Conductivity or specific conductance of an electrolyte solution is a measure of its ability to conduct electricity. The SI unit of conductivity is siemens per meter (S/m). Conductivity measurements are used routinely in many industrial and environmental applications as a fast, inexpensive and reliable way of measuring the ionic content in a solution. For example, the measurement of product conductivity is a typical way to monitor and continuously trend the performance of water purification systems. In many cases, conductivity is linked directly to the total dissolved solids (TDS). High-quality deionized water has a conductivity of : \kappa = 0.05501 \pm 0.0001 μS/cm at 25 °C. This corresponds to a specific resistivity of : \rho = 18.18 \pm 0.03 MΩ⋅cm. The preparation of salt solutions often takes place in unsealed beakers. In this case the conductivity of purified water often is 10 to 20 times higher. A discussion can be found below. Typical drinking water is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Analytical Chemistry
Analytical skill, Analytical chemistry studies and uses instruments and methods to Separation process, separate, identify, and Quantification (science), quantify matter. In practice, separation, identification or quantification may constitute the entire analysis or be combined with another method. Separation isolates analytes. Qualitative inorganic analysis, Qualitative analysis identifies analytes, while Quantitative analysis (chemistry), quantitative analysis determines the numerical amount or concentration. Analytical chemistry consists of classical, wet chemistry, wet chemical methods and modern analytical techniques. Classical qualitative methods use separations such as Precipitation (chemistry), precipitation, Extraction (chemistry), 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. Ins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bad Gastein
Bad Gastein ( is a spa town in the St. Johann im Pongau District. Picturesquely situated in a high valley of the Hohe Tauern mountain range, it is known for the Gastein waterfall and a variety of grand hotel buildings. Geography Bad Gastein is located in the historic Pongau District. It stretches along the upper Gastein Valley following the course of the Gastein Ache creek. The valley separates the Hohe Tauern Ankogel Group in the east from the Goldberg Group in the west. The town centre is located at the Gastein waterfall, about 1,000 metres (3,300 ft) above sea level. Transportation The Gastein valley is accessible by the Tauern Railway, a major railroad running from Schwarzach im Pongau in the north across the Tauern Railway Tunnel to Spittal an der Drau, Carinthia in the south. Frequent EuroCity and InterCity trains going along this route connect Bad Gastein with many Austrian cities like Vienna, Linz, Salzburg and Graz. Spa and therapy The German word "B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Austria
Austria, formally the Republic of Austria, is a landlocked country in Central Europe, lying in the Eastern Alps. It is a federation of nine Federal states of Austria, states, of which the capital Vienna is the List of largest cities in Austria, most populous city and state. Austria is bordered by Germany to the northwest, the Czech Republic to the north, Slovakia to the northeast, Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the west. The country occupies an area of and has Austrians, a population of around 9 million. The area of today's Austria has been inhabited since at least the Paleolithic, Paleolithic period. Around 400 BC, it was inhabited by the Celts and then annexed by the Roman Empire, Romans in the late 1st century BC. Christianization in the region began in the 4th and 5th centuries, during the late Western Roman Empire, Roman period, followed by the arrival of numerous Germanic tribes during the Migration Period. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friedrich Kohlrausch (physicist)
Friedrich Wilhelm Georg Kohlrausch (14 October 1840 – 17 January 1910) was a German physicist who investigated the conductive properties of electrolytes and contributed to knowledge of their behaviour. He also investigated elasticity, thermoelasticity, and thermal conduction as well as magnetic and electrical precision measurements. Nowadays, Friedrich Kohlrausch is classed as one of the most important experimental physicists. His early work helped to extend the absolute system of Carl Friedrich Gauss and Wilhelm Weber to include electrical and magnetic measuring units. Biography Education Son of Rudolf Kohlrausch, Friedrich Wilhelm Georg Kohlrausch was born on October 14, 1840, in Rinteln, Germany. After studying physics at Erlangen and Göttingen, Friedrich Kohlrausch completed his doctorate in Göttingen. Teaching After a two-year work as a lecturer in Frankfurt, Kohlrausch was appointed a professor of physics at the University of Göttingen (1866–70). During 1870 Ko ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfuric Acid
Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid (English in the Commonwealth of Nations, Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, and hydrogen, with the molecular formula . It is a colorless, odorless, and Viscosity, viscous liquid that is Miscibility, miscible with water. Pure sulfuric acid does not occur naturally due to its Dehydration reaction, strong affinity to water vapor; it is Hygroscopy, hygroscopic and readily absorbs water vapor from the Atmosphere of Earth, air. Concentrated sulfuric acid is a strong oxidant with powerful dehydrating properties, making it highly corrosive towards other materials, from rocks to metals. Phosphorus pentoxide is a notable exception in that it is not dehydrated by sulfuric acid but, to the contrary, dehydrates sulfuric acid to sulfur trioxide. Upon addition of sulfuric acid to water, a considerable amount of heat is releas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Behrend
Anton Friedrich Robert Behrend (17 December 1856 – 15 September 1926) was a German analytical organic chemist who made pioneering studies of stereochemistry and Isomer, isomerism. He was also the first to synthesize uric acid and introduced potentiometric titration. The Behrend rearrangement reaction of nitrones is named after him. Behrend was born in Harburg (quarter), Harburg to Karl, a trader and his wife Louise Elisabeth Margarethe Carol née Himbeck. He grew up in Hamburg. He joined the infantry regiment in 1876 and studied law for some time and then shifted to physics under Emil Warburg, Emil Gabriel Warburg. In 1877 and 1878, he tried to study chemistry at Leipzig under Hermann Kolbe, Herman Kolbe but was not accepted as he knew nothing. He then worked under Gustav Heinrich Wiedemann and received a doctorate in organic chemistry in 1881. He became a professor in 1889 and in 1897, he moved to the Leibniz University Hannover, Technical College of Hannover working on stereoch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titration
Titration (also known as titrimetry and volumetric analysis) is a common laboratory method of Quantitative research, quantitative Analytical chemistry, chemical analysis to determine the concentration of an identified analyte (a substance to be analyzed). A reagent, termed the ''titrant'' or ''titrator'', is prepared as a standard solution of known concentration and volume. The titrant reacts with a Solution (chemistry), solution of ''analyte'' (which may also be termed the ''titrand'') to determine the analyte's concentration. The volume of titrant that reacted with the analyte is termed the ''titration volume''. History and etymology The word "titration" descends from the French word ''titrer'' (1543), meaning the proportion of gold or silver in coins or in works of gold or silver; i.e., a measure of fineness or purity. ''Tiltre'' became ''titre'', which thus came to mean the "fineness of alloyed gold", and then the "concentration of a substance in a given sample". In 1828, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reaction Mixture
A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. When chemical reactions occur, the atoms are rearranged and the reaction is accompanied by an energy change as new products are generated. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the nuclei (no change to the elements present), and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive elements where both electronic and nuclear changes can occur. The substance (or substances) initially involved in a chemical reaction are called reactants or reagents. Chemical reactions are usually characterized by a chemical change, and they yield one or more products, which usually have properties different from the reactants. Reactions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equivalence Point
The equivalence point, or stoichiometric point, of a chemical reaction is the point at which chemically equivalent quantities of reactants have been mixed. For an acid-base reaction the equivalence point is where the moles of acid and the moles of base would neutralize each other according to the chemical reaction. This does not necessarily imply a 1:1 molar ratio of acid:base, merely that the ratio is the same as in the chemical reaction. It can be found by means of an indicator, for example phenolphthalein or methyl orange. The endpoint (related to, but not the same as the equivalence point) refers to the point at which the indicator changes color in a colorimetric titration. Methods to determine the equivalence point Different methods to determine the equivalence point include: ;pH indicator: A pH indicator is a substance that changes color in response to a chemical change. An acid-base indicator (e.g., phenolphthalein) changes color depending on the pH. Redox indicators ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
