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Lyate Ion
In chemistry, a lyate ion is the anion derived by the deprotonation of a solvent molecule. For example, a hydroxide ion is formed by the deprotonation of water, and methoxide () is the anion formed by the deprotonation of methanol. Its counterpart is a lyonium ion, the cation formed by the protonation of a solvent molecule. Lyonium and lyate ions, resulting from molecular autoionization, contribute to the molar conductivity of protolytic solvents. Examples See also *Lyonium ion, a protonated solvent molecule *Ate complex * Ion transport number *Ionic atmosphere Ionic Atmosphere is a concept employed in Debye-Hückel theory which explains the electrolytic conductivity behaviour of solutions. It can be generally defined as the area at which a charged entity is capable of attracting an entity of the opposit ... References Anions Bases (chemistry) {{Chem-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemistry
Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science that covers the Chemical element, elements that make up matter to the chemical compound, compounds made of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during a Chemical reaction, reaction with other Chemical substance, substances. Chemistry also addresses the nature of chemical bonds in chemical compounds. In the scope of its subject, chemistry occupies an intermediate position between physics and biology. It is sometimes called the central science because it provides a foundation for understanding both Basic research, basic and Applied science, applied scientific disciplines at a fundamental level. For example, chemistry explains aspects of plant growth (botany), the formation of igneous rocks (geology), how atmospheric ozone is formed and how environmental pollutants are degraded (ecology), the properties ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protonation
In chemistry, protonation (or hydronation) is the adding of a proton (or hydron, or hydrogen cation), (H+) to an atom, molecule, or ion, forming a conjugate acid. (The complementary process, when a proton is removed from a Brønsted–Lowry acid, is deprotonation.) Some examples include *The protonation of water by sulfuric acid: *:H2SO4 + H2O H3O+ + *The protonation of isobutene in the formation of a carbocation: *:(CH3)2C=CH2 + HBF4 (CH3)3C+ + *The protonation of ammonia in the formation of ammonium chloride from ammonia and hydrogen chloride: *:NH3( g) + HCl( g) → NH4Cl( s) Protonation is a fundamental chemical reaction and is a step in many stoichiometric and catalytic processes. Some ions and molecules can undergo more than one protonation and are labeled polybasic, which is true of many biological macromolecules. Protonation and deprotonation (removal of a proton) occur in most acid–base reactions; they are the core of most acid–base reaction theories. A Brønst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ionic Atmosphere
Ionic Atmosphere is a concept employed in Debye-Hückel theory which explains the electrolytic conductivity behaviour of solutions. It can be generally defined as the area at which a charged entity is capable of attracting an entity of the opposite charge. Asymmetry, or relaxation effect If an electrical potential is applied to an electrolytic solution, a positive ion will move towards the negative electrode and drag along an entourage of negative ions with it. The more concentrated the solution, the closer these negative ions are to the positive ion and thus the greater the resistance experienced by the positive ion. This influence on the speed of an ion is known as the "Asymmetry effect" because the ionic atmosphere moving around the ion is not symmetrical; the charge density behind is greater than in the front, slowing the motion of the ion. Laidler K.J. and Meiser J.H., ''Physical Chemistry'' (Benjamin/Cummings 1982) p.269 The time required to form a new ionic atmosphere on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ion Transport Number
In chemistry, ion transport number, also called the transference number, is the fraction of the total electric current carried in an electrolyte by a given ionic species : :t_i = \frac Differences in transport number arise from differences in electrical mobility. For example, in an aqueous solution of sodium chloride, less than half of the current is carried by the positively charged sodium ions (cations) and more than half is carried by the negatively charged chloride ions (anions) because the chloride ions are able to move faster, i.e., chloride ions have higher mobility than sodium ions. The sum of the transport numbers for all of the ions in solution always equals unity: :\sum_i t_i = 1 The concept and measurement of transport number were introduced by Johann Wilhelm Hittorf in the year 1853. Liquid junction potential can arise from ions in a solution having different ion transport numbers. At zero concentration, the limiting ion transport numbers may be expressed in terms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ate Complex
In chemistry, an ate complex is a salt formed by the reaction of a Lewis acid with a Lewis base whereby the central atom (from the Lewis acid) increases its valence and gains a negative formal charge. (In this definition, the meaning of valence is equivalent to coordination number). Often in chemical nomenclature the term ''ate'' is suffixed to the element in question. For example, the ate complex of a boron compound is called a borate. Thus trimethylborane and methyllithium react to form the ate compound , lithium tetramethylborate(1-). This concept was introduced by Georg Wittig in 1958. Ate complexes are common for metals, including the transition metals (groups 3-11), as well as the metallic or semi-metallic elements of group 2, 12, and 13. They are also well-established for third-period or heavier elements of groups 14–18 in their higher oxidation states. Ate complexes are a counterpart to onium ions. Lewis acids form ate ions when the central atom reacts with a do ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lyonium Ion
In chemistry, a lyonium ion is the cation derived by the protonation of a solvent molecule. For example, a hydronium ion is formed by the protonation of water, and is the cation formed by the protonation of methanol. Its counterpart is a lyate ion, the anion formed by the deprotonation of a solvent molecule. Lyonium and lyate ions, resulting from molecular autoionization, contribute to the molar conductivity of protolytic solvents. Examples See also * Lyate ion, a deprotonated solvent molecule *Onium ion, a protonated molecule more generally * Ion transport number *Ionic atmosphere Ionic Atmosphere is a concept employed in Debye-Hückel theory which explains the electrolytic conductivity behaviour of solutions. It can be generally defined as the area at which a charged entity is capable of attracting an entity of the opposit ... References Acids Cations {{Chem-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molar Conductivity
The molar conductivity of an electrolyte solution is defined as its conductivity divided by its molar concentration. : \Lambda_\text = \frac, where: : ''κ'' is the measured conductivity (formerly known as specific conductance), : ''c'' is the molar concentration of the electrolyte. The SI unit of molar conductivity is siemens metres squared per mole (S m2 mol−1). However, values are often quoted in S cm2 mol−1. In these last units, the value of Λm may be understood as the conductance of a volume of solution between parallel plate electrodes one centimeter apart and of sufficient area so that the solution contains exactly one mole of electrolyte. Variation of molar conductivity with dilution There are two types of electrolytes: strong and weak. Strong electrolytes usually undergo complete ionization, and therefore they have higher conductivity than weak electrolytes, which undergo only partial ionization. For strong electrolytes, such as salts, strong ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Autoionization
In chemistry, molecular autoionization (or self-ionization) is a chemical reaction between molecules of the same substance to produce ions. If a pure liquid partially dissociates into ions, it is said to be self-ionizing. In most cases the oxidation number on all atoms in such a reaction remains unchanged. Such autoionization can be ''protic'' ( transfer), or ''non-protic''. Examples Protic solvents Protic solvents often undergo some autoionization (in this case autoprotolysis): *2 H2O H3O+ + OH- **The self-ionization of water is particularly well studied, due to its implications for acid-base chemistry of aqueous solutions. *2 NH3 NH4+ + NH2- *2 H2SO4 H3SO4+ + HSO4- *3 HF H2F+ + HF2- **Here proton transfer between two HF combines with homoassociation of and a third HF to form Non-protic solvents *2 PF5 PF6- + PF4+ *N2O4 NO+ + NO3- ** Here the nitrogen oxidation numbers change from (+4 and +4) to (+3 and +5). *2 BrF3 BrF2+ + BrF4- These solvents all possess ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cation
An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convention. The net charge of an ion is not zero because its total number of electrons is unequal to its total number of protons. A cation is a positively charged ion with fewer electrons than protons while an anion is a negatively charged ion with more electrons than protons. Opposite electric charges are pulled towards one another by electrostatic force, so cations and anions attract each other and readily form ionic compounds. Ions consisting of only a single atom are termed atomic or monatomic ions, while two or more atoms form molecular ions or polyatomic ions. In the case of physical ionization in a fluid (gas or liquid), "ion pairs" are created by spontaneous molecule collisions, where each generated pair consists of a free electron and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anion
An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convention. The net charge of an ion is not zero because its total number of electrons is unequal to its total number of protons. A cation is a positively charged ion with fewer electrons than protons while an anion is a negatively charged ion with more electrons than protons. Opposite electric charges are pulled towards one another by electrostatic force, so cations and anions attract each other and readily form ionic compounds. Ions consisting of only a single atom are termed atomic or monatomic ions, while two or more atoms form molecular ions or polyatomic ions. In the case of physical ionization in a fluid (gas or liquid), "ion pairs" are created by spontaneous molecule collisions, where each generated pair consists of a free electron and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lyonium Ion
In chemistry, a lyonium ion is the cation derived by the protonation of a solvent molecule. For example, a hydronium ion is formed by the protonation of water, and is the cation formed by the protonation of methanol. Its counterpart is a lyate ion, the anion formed by the deprotonation of a solvent molecule. Lyonium and lyate ions, resulting from molecular autoionization, contribute to the molar conductivity of protolytic solvents. Examples See also * Lyate ion, a deprotonated solvent molecule *Onium ion, a protonated molecule more generally * Ion transport number *Ionic atmosphere Ionic Atmosphere is a concept employed in Debye-Hückel theory which explains the electrolytic conductivity behaviour of solutions. It can be generally defined as the area at which a charged entity is capable of attracting an entity of the opposit ... References Acids Cations {{Chem-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methanol
Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical and the simplest aliphatic alcohol, with the formula C H3 O H (a methyl group linked to a hydroxyl group, often abbreviated as MeOH). It is a light, volatile, colourless, flammable liquid with a distinctive alcoholic odour similar to that of ethanol (potable alcohol). A polar solvent, methanol acquired the name wood alcohol because it was once produced chiefly by the destructive distillation of wood. Today, methanol is mainly produced industrially by hydrogenation of carbon monoxide. Methanol consists of a methyl group linked to a polar hydroxyl group. With more than 20 million tons produced annually, it is used as a precursor to other commodity chemicals, including formaldehyde, acetic acid, methyl tert-butyl ether, methyl benzoate, anisole, peroxyacids, as well as a host of more specialised chemicals. Occurrence Small amounts of methanol are present in normal, healthy hu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
