|
Milliequivalent
An equivalent (symbol: officially equiv; unofficially but often Eq) is the amount of a substance that reacts with (or is ''equivalent'' to) an arbitrary amount (typically one mole) of another substance in a given chemical reaction. It is an archaic unit of measurement that was used in chemistry and the biological sciences (see '). The mass of an equivalent is called its equivalent weight. Formula : ''milligrams to = mg x V / MW'' :: Example for elemental compounds: (mg element / elemental compound mass fraction) x V / MV : '' to milligrams = mEq x MW / V'' Common examples mEq to milligram Milligram to mEq Formal definition In a more formal definition, the ''equivalent'' is the amount of a substance needed to do one of the following: * react with or supply one mole of hydrogen ions () in an acid–base reaction * react with or supply one mole of electrons in a redox reaction. The "hydrogen ion" and the "electron" in these examples are respectively called the "reactio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium
Potassium is the chemical element with the symbol K (from Neo-Latin ''kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure. It was first isolated from potash, the ashes of plants, from which its name derives. In the periodic table, potassium is one of the alkali metals, all of which have a single valence electron in the outer electron shell, that is easily removed to create an ion with a positive charge – a cation, that combines with anions to form salts. Potassium in nature occurs only in ionic salts. Elemental potassium reacts vigorously with water, generating sufficient heat to ignite hydrogen emitted in the reaction, and burning with a lilac- colored flame. It is found dissolved in sea water (which is 0.04% potassium by weight), and occurs in many minerals such as orthocl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Gluconate
Potassium gluconate is the potassium salt of the conjugate base of gluconic acid. It is also referred to as 2,3,4,5,6-pentahydroxycaproic acid potassium salt, D-gluconic acid potassium salt, or potassium D-gluconate. It contains 16.69% potassium by mass. Thus 5.99 g of potassium gluconate contains 1 g of potassium. It has a density of 1.73 g/cm3. Dietary uses Potassium gluconate is used as a mineral supplement and sequestrant. It is sold over-the-counter as tablets or capsules providing up to 593 mg of potassium gluconate, thereby containing 99 mg or 2.53 milliequivalents of elemental potassium. This is the permissible upper limit for each tablet or capsule of over-the-counter potassium supplements sold in the US. Potassium gluconate is also sold over-the-counter as bulk powder. As a food additive, potassium gluconate is used as an acidity regulator and yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equivalent Weight
In chemistry, equivalent weight (also known as gram equivalent) is the mass of one equivalent, that is the mass of a given substance which will combine with or displace a fixed quantity of another substance. The equivalent weight of an element is the mass which combines with or displaces 1.008 gram of hydrogen or 8.0 grams of oxygen or 35.5 grams of chlorine. These values correspond to the atomic weight divided by the usual valence; for oxygen as example that is 16.0 g / 2 = 8.0 g. For acid–base reactions, the equivalent weight of an acid or base is the mass which supplies or reacts with one mole of hydrogen cations (). For redox reactions, the equivalent weight of each reactant supplies or reacts with one mole of electrons (e−) in a redox reaction. Equivalent weight has the units of mass, unlike atomic weight, which is now used as a synonym for relative atomic mass and is dimensionless. Equivalent weights were originally determined by experiment, but (insofar as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Substance
A chemical substance is a form of matter having constant chemical composition and characteristic properties. Some references add that chemical substance cannot be separated into its constituent elements by physical separation methods, i.e., without breaking chemical bonds. Chemical substances can be simple substances (substances consisting of a single chemical element), chemical compounds, or alloys. Chemical substances are often called 'pure' to set them apart from mixtures. A common example of a chemical substance is pure water; it has the same properties and the same ratio of hydrogen to oxygen whether it is isolated from a river or made in a laboratory. Other chemical substances commonly encountered in pure form are diamond (carbon), gold, table salt ( sodium chloride) and refined sugar ( sucrose). However, in practice, no substance is entirely pure, and chemical purity is specified according to the intended use of the chemical. Chemical substances exist as so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorine
Chlorine is a chemical element with the symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine is a yellow-green gas at room temperature. It is an extremely reactive element and a strong oxidising agent: among the elements, it has the highest electron affinity and the third-highest electronegativity on the revised Pauling scale, behind only oxygen and fluorine. Chlorine played an important role in the experiments conducted by medieval alchemists, which commonly involved the heating of chloride salts like ammonium chloride ( sal ammoniac) and sodium chloride (common salt), producing various chemical substances containing chlorine such as hydrogen chloride, mercury(II) chloride (corrosive sublimate), and hydrochloric acid (in the form of ). However, the nature of free chlorine gas as a separate substance was only recognised aroun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Element
A chemical element is a species of atoms that have a given number of protons in their nuclei, including the pure substance consisting only of that species. Unlike chemical compounds, chemical elements cannot be broken down into simpler substances by any chemical reaction. The number of protons in the nucleus is the defining property of an element, and is referred to as its atomic number (represented by the symbol ''Z'') – all atoms with the same atomic number are atoms of the same element. Almost all of the baryonic matter of the universe is composed of chemical elements (among rare exceptions are neutron stars). When different elements undergo chemical reactions, atoms are rearranged into new compounds held together by chemical bonds. Only a minority of elements, such as silver and gold, are found uncombined as relatively pure native element minerals. Nearly all other naturally occurring elements occur in the Earth as compounds or mixtures. Air is primarily a mixture ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, and highly combustible. Hydrogen is the most abundant chemical substance in the universe, constituting roughly 75% of all normal matter.However, most of the universe's mass is not in the form of baryons or chemical elements. See dark matter and dark energy. Stars such as the Sun are mainly composed of hydrogen in the plasma state. Most of the hydrogen on Earth exists in molecular forms such as water and organic compounds. For the most common isotope of hydrogen (symbol 1H) each atom has one proton, one electron, and no neutrons. In the early universe, the formation of protons, the nuclei of hydrogen, occurred during the first second after the Big Bang. The emergence of neutral hydrogen atoms throughout the universe occur ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grand Dictionnaire Universel Du XIXe Siècle
The ''Grand dictionnaire universel du XIXe siècle'' (''Great Universal Dictionary of the 19th Century''), often called the ''Grand Larousse du dix-neuvième'', is a French encyclopedic dictionary. It was planned, directed, published, and to a substantial degree written by Pierre Larousse, though he also relied on anonymous fellow contributors and though he died in 1875, before its completion. The publication of the ''Grand dictionnaire universel'' in 15 volumes of 1500 pages extended from 1866 to 1876. Two supplements were published in 1877 and 1890. Description Volumes 1–15, covering A-Z, were issued from 1866 to 1876. A supplement (Volume 16) was published in 1877, and a second supplement (Volume 17), in 1890.Sevol. 17, pp. 2023–2024 The Larousse firm also published further supplements in the form of a magazine called ''Revue encyclopédique'' (1891-1900) then ''Revue universelle'' (1900-1905). Unlike Émile Littré's contemporary dictionary, the ''Grand Larousse'' is pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Redox Reaction
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a decrease in the oxidation state. There are two classes of redox reactions: * ''Electron-transfer'' – Only one (usually) electron flows from the reducing agent to the oxidant. This type of redox reaction is often discussed in terms of redox couples and electrode potentials. * ''Atom transfer'' – An atom transfers from one substrate to another. For example, in the rusting of iron, the oxidation state of iron atoms increases as the iron converts to an oxide, and simultaneously the oxidation state of oxygen decreases as it accepts electrons released by the iron. Although oxidation reactions are commonly associated with the formation of oxides, other chemical species can serve the same function. In hydrogenation, C=C (and other) bonds a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pierre Larousse
Pierre Athanase Larousse (23 October 18173 January 1875) was a French grammarian, lexicographer and encyclopaedist. He published many of the outstanding educational and reference works of 19th-century France, including the 15-volume '' Grand dictionnaire universel du XIXe siècle''. Early life Pierre Larousse was born in Toucy, where his father was a blacksmith. At the age of sixteen he won a scholarship at the teaching school in Versailles. Four years later, he returned to Toucy to teach in a primary school, but became frustrated by the archaic and rigid teaching methods. In 1840 he moved to Paris to improve his own education by taking free courses. Career From 1848 to 1851 he taught at a private boarding school, where he met his future wife, Suzanne Caubel (although they did not marry until 1872). Together, in 1849, they published a French language course for children. In 1851 he met Augustin Boyer, another disillusioned ex-teacher, and together they founded the ''Librai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
%2C_black_and_white.png "Click for more on -> Chemical Element")
.JPG "Click for more on -> Grand Dictionnaire Universel Du XIXe Siècle")
