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Encyclopedia > Chemical reaction

eaw eaw eaw die scott betty gaggle pooful lump Chemical reaction (or any of its capitalisation variants) can mean: Chemical reaction , the process Chemical Reaction (artscene group), the artscene group (cRO) Category: ...


A chemical reaction is a process that always results in the interconversion of chemical substances.[1] The substance or substances initially involved in a chemical reaction are called reactants. Chemical reactions are usually characterized by a chemical change, and they yield one or more products which are, in general, different from the reactants. Classically, chemical reactions encompass changes that strictly involve the motion of electrons in the forming and breaking of chemical bonds, although the general concept of a chemical reaction, in particular the notion of a chemical equation, is applicable to transformations of elementary particles, as well as nuclear reactions. Water and steam are two different forms of the same chemical substance A chemical substance is a material with a definite chemical composition. ... In chemistry, the reactants are the substances that exist at the start of a chemical reaction. ... Combustion, an example of a chemical change. ... Properties The electron (also called negatron, commonly represented as e−) is a subatomic particle. ... A chemical bond is the physical process responsible for the attractive interactions between atoms and molecules, and that which confers stability to diatomic and polyatomic chemical compounds. ... A chemical equation is a symbolic representation of a chemical reaction. ... In this Feynman diagram, an electron and positron annihilate and become a quark-antiquark pair. ... In nuclear physics, a nuclear reaction is a process in which two nuclei or nuclear particles collide to produce products different from the initial particles. ...



Different chemical reactions are used in combinations in chemical synthesis in order to get a desired product. In biochemistry, series of chemical reactions catalyzed by enzymes form metabolic pathways, by which syntheses and decompositions ordinarily impossible in conditions within a cell are performed. In chemistry, chemical synthesis is purposeful execution of chemical reactions in order to get a product, or several products. ... Wöhler observes the synthesis of urea. ... Catalyst redirects here. ... Neuraminidase ribbon diagram An enzyme (in Greek en = in and zyme = blend) is a protein, or protein complex, that catalyzes a chemical reaction and also controls the 3D orientation of the catalyzed substrates. ... In biochemistry, a metabolic pathway is a series of chemical reactions occurring within a cell, catalyzed by enzymes, and resulting in either the formation of a metabolic product to be used or stored by the cell (metabolic sink), or the initiation of another metabolic pathway (then called a flux generating...

Contents

Reaction types

The large diversity of chemical reactions and approaches to their study results in the existence of several concurring, often overlapping, ways of classifying them. Below are examples of widely used terms for describing common kinds of reactions. This page aims to list well-known chemical reactions, name reactions, name reagents, and name rules to stimulate the creation of Wikipedia articles. ...

N2 + 3 H2 → 2 NH3
2 H2O → 2 H2 + O2
2 Na(s) + 2 HCl(aq) → 2 NaCl(aq) + H2(g)
  • Metathesis or Double displacement reaction, in which two compounds exchange ions or bonds to form different compounds:
NaCl(aq) + AgNO3(aq) → NaNO3(aq) + AgCl(s)
  • Acid-base reactions, broadly characterized as reactions between an acid and a base, can have different definitions depending on the acid-base concept employed. Some of the most common are:
  • Arrhenius definition: Acids dissociate in water releasing H3O+ ions; bases dissociate in water releasing OH- ions.
  • Brønsted-Lowry definition: Acids are proton (H+) donors; bases are proton acceptors. Includes the Arrhenius definition.
  • Lewis definition: Acids are electron-pair acceptors; bases are electron-pair donors. Includes the Brønsted-Lowry definition.
  • Redox reactions, in which changes in oxidation numbers of atoms in involved species occur. Those reactions can often be interpreted as transferences of electrons between different molecular sites or species. A typical example of redox rection is:
2 S2O32−(aq) + I2(aq) → S4O62−(aq) + 2 I(aq)

In which I2 is reduced to I- and S2O32- (thiosulfate anion) is oxidized to S4O62-. In chemistry, isomerization is the transformation of a molecule into a different isomer. ... Main article: stereochemistry Stereoisomerism is the arrangement of atoms in molecules whose connectivity remains the same but their arrangement in space is different in each isomer. ... Combination Reaction is a reaction in which two or more substances are chemically bonded together to produce a product. ... In chemistry, chemical synthesis is purposeful execution of chemical reactions in order to get a product, or several products. ... General Name, symbol, number nitrogen, N, 7 Chemical series nonmetals Group, period, block 15, 2, p Appearance colorless gas Standard atomic weight 14. ... This article is about the chemistry of hydrogen. ... For other uses, see Ammonia (disambiguation). ... Chemical decomposition or analysis is the fragmentation of a chemical compound into elements or smaller compounds. ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... This article is about the chemical element and its most stable form, or dioxygen. ... It has been suggested that this article or section be merged with Single replacement scheme. ... Substitution in the context of organic chemistry has the general meaning of replacing an atom, a functional group, or a substituent in a molecule. ... In chemistry, the reactivity series is a series of metals, in order of reactivity from highest to lowest. ... For sodium in the diet, see Salt. ... R-phrases , S-phrases , , , , Flash point non-flammable Supplementary data page Structure and properties n, εr, etc. ... R-phrases 36 S-phrases none Flash point Non-flammable Related Compounds Other anions NaF, NaBr, NaI Other cations LiCl, KCl, RbCl, CsCl, MgCl2, CaCl2 Related salts Sodium acetate Supplementary data page Structure and properties n, εr, etc. ... Metathesis is a bimolecular process involving the exchange of bonds between the two reacting chemical species, which results in the creation of products with similar or identical bonding affiliations. ... This article is about the electrically charged particle. ... R-phrases , S-phrases , , , , Flash point non-flammable Supplementary data page Structure and properties n, εr, etc. ... Made of Porn and sex things Inhalation respiratory irritation Skin May cause irritation. ... Related Compounds Other anions silver(I) fluoride, silver bromide, silver iodide Except where noted otherwise, data are given for materials in their standard state (at 25 Â°C, 100 kPa) Infobox disclaimer and references Silver chloride is a chemical compound with the chemical formula AgCl. ... An acid-base reaction is a chemical reaction between an acid and a base. ... For other uses, see acid (disambiguation). ... Acids and bases: Acid-base extraction Acid-base reaction Acid dissociation constant Acidity function Buffer solutions pH Proton affinity Self-ionization of water Acids: Lewis acids Mineral acids Organic acids Strong acids Superacids Weak acids Bases: Lewis bases Organic bases Strong bases Superbases Non-nucleophilic bases Weak bases edit In... An acid-base reaction is a chemical reaction between an acid and a base. ... In chemistry, the Brønsted-Lowry acid-base theory or Brønsted-Lowry concept is an acid-base theory describing the reaction mechanism between acids and bases, and was independently proposed by Johannes Nicolaus Brønsted and Thomas Martin Lowry in 1923. ... An acid-base reaction is a chemical reaction between an acid and a base. ... The most fundamental reactions in chemistry are the redox processes. ... Not to be confused with oxidation state. ... It has been suggested that thiosulfate ion be merged into this article or section. ...

  • Combustion, a kind of redox reaction in which any combustible substance combines with an oxidizing element, usually oxygen, to generate heat and form oxidized products. The term combustion is usually used for only large-scale oxidation of whole molecules, i.e. a controlled oxidation of a single functional group is not combustion.
C10H8+ 12 O2 → 10 CO2 + 4 H2O
CH2S + 6 F2CF4 + 2 HF + SF6

Organic reactions encompass a wide assortment of reactions involving compounds which have carbon as the main element in their molecular structure. The reactions in which an organic compound may take part are largely defined by its functional groups. Defined in opposition to inorganic reactions. Reactions can also be classified according to their mechanism, some typical examples being: This article is about the chemical reaction combustion. ... Distinguished from fluorene and fluorone. ... Carbon tetrafluoride, CF4, is a carbon fluoride. ... Hydrogen fluoride is a chemical compound with the formula HF. Together with hydrofluoric acid, it is the principal industrial source of fluorine and hence the precursor to many important compounds including pharmaceuticals and polymers (e. ... Sulfur hexafluoride is an inorganic compound with the formula . ... Organic reactions are chemical reactions involving organic compounds. ... Benzene is the simplest of the arenes, a family of organic compounds An organic compound is any member of a large class of chemical compounds whose molecules contain carbon. ... For other uses, see Carbon (disambiguation). ... In organic chemistry, functional groups (or moieties) are specific groups of atoms within molecules, that are responsible for the characteristic chemical reactions of those molecules. ... An inorganic chemical reaction describes a chemical reaction of an inorganic compound. ...

Disproportionation is a concept in chemistry and is a redox reaction where a reactant is both oxidised and reduced in the same chemical reaction. ... The hypochlorite ion The hypochlorite ion is ClO−. A hypochlorite compound is a chemical compound containing this group, with chlorine in oxidation state +1. ... Enol (or, more officially, but less commonly: alkenol) is an alkene with hydroxyl group on one of the carbon atoms of the double bond. ... In chemistry, radicals (often referred to as free radicals) are atomic or molecular species with unpaired electrons on an otherwise open shell configuration. ... In chemistry a carbene is a short-lived and highly reactive organic molecule with a divalent carbon atom with only six valence electrons and the general formula: R1R2C: . The carbon atom is sp2 hybridised with an empty p-orbital extending above and below a plane containing R1 and R2 and...

Chemical kinetics

Main article: Chemical kinetics

The rate of a chemical reaction is a measure of how the concentration or pressure of the involved substances changes with time. Analysis of reaction rates is important for several applications, such as in chemical engineering or in chemical equilibrium study. Rates of reaction depends basically on: In physical chemistry, chemical kinetics or reaction kinetics is the study of reaction rates in a chemical reaction. ... Iron rusting - a chemical reaction with a slow reaction rate. ... For other uses, see Concentration (disambiguation). ... This article is about pressure in the physical sciences. ... Chemical engineers design, construct and operate plants Chemical engineering is the branch of engineering that deals with the application of physical science (e. ... A burette, an apparatus for carrying out acid-base titration, is an important part of equilibrium chemistry. ...

  • Reactant concentrations, which usually make the reaction happen at a faster rate if raised through increased collisions per unit time,
  • Surface area available for contact between the reactants, in particular solid ones in heterogeneous systems. Larger surface area leads to higher reaction rates.
  • Pressure, by increasing the pressure, you decrease the volume between molecules. This will increase the frequency of collisions of molecules.
  • Activation energy, which is defined as the amount of energy required to make the reaction start and carry on spontaneously. Higher activation energy implies that the reactants need more energy to start than a reaction with a lower activation energy.
  • Temperature, which hastens reactions if raised, since higher temperature increases the energy of the molecules, creating more collisions per unit time,
  • The presence or absence of a catalyst. Catalysts are substances which change the pathway (mechanism) of a reaction which in turn increases the speed of a reaction by lowering the activation energy needed for the reaction to take place. A catalyst is not destroyed or changed during a reaction, so it can be used again.
  • For some reactions, the presence of electromagnetic radiation, most notably ultra violet, is needed to promote the breaking of bonds to start the reaction. This is particularly true for reactions involving radicals.

Reaction rates are related to the concentrations of substances involved in reactions, as quantified by the rate law of each reaction. Note that some reactions have rates that are independent of reactant concentrations. These are called zero order reactions. A reactant or reagent is any substance initially present in a chemical reaction. ... Area is the measure of how much exposed area any two dimensional object has. ... This article is about pressure in the physical sciences. ... The sparks generated by striking steel against a flint provide the activation energy to initiate combustion in this Bunsen burner. ... For other uses, see Temperature (disambiguation). ... It has been suggested that this article or section be merged into Catalysis. ... The sparks generated by striking steel against a flint provide the activation energy to initiate combustion in this Bunsen burner. ... This box:      Electromagnetic (EM) radiation is a self-propagating wave in space with electric and magnetic components. ... Note: Ultraviolet is also the name of a 1998 UK television miniseries about vampires. ... In chemistry, radicals (often referred to as free radicals) are atomic or molecular species with unpaired electrons on an otherwise open shell configuration. ... This page refers to concentration in the chemical sense. ... For a chemical reaction, the rate law or rate equation is an equation which links the reaction rate with concentrations or pressures of reactants. ... A rate law is an equation that relates concentrations of reactants to the reaction rate. ...


See also

This page aims to list well-known chemical reactions, name reactions, name reagents, and name rules to stimulate the creation of Wikipedia articles. ... Organic reactions are chemical reactions involving organic compounds. ... An inorganic chemical reaction describes a chemical reaction of an inorganic compound. ... This is a list of important publications in chemistry, organized by field. ... Stoichiometry (sometimes called reaction stoichiometry to distinguish it from composition stoichiometry) is the calculation of quantitative (measurable) relationships of the reactants and products in chemical reactions (chemical equations). ... In a chemical reaction system the stoichiometric coefficient of the i-th component is defined as or where Ni is the number of molecules of i and ξ is the progress variable or extent of reaction. ... It has been suggested that this article or section be merged into transition state. ... Stoichiometry is the quantitative relationship between reactants and products in a chemical reaction. ... Thermodynamic databases contain information about thermodynamic properties for substances, the most important being enthalpy, entropy, and Gibbs free energy. ... In mathematics, a coefficient is a multiplicative factor that belongs to a certain object such as a variable (for example, the coefficients of a polynomial), a basis vector, a basis function and so on. ...

References

  1. ^ International Union of Pure and Applied Chemistry. "chemical reaction". Compendium of Chemical Terminology Internet edition.
IUPAC logo The International Union of Pure and Applied Chemistry (IUPAC) (Pronounced as eye-you-pack) is an international non-governmental organization established in 1919 devoted to the advancement of chemistry. ... Compendium of Chemical Terminology (ISBN 0-86542-684-8) is a book published by IUPAC containing internationally accepted definitions for terms in chemistry. ...

  Results from FactBites:
 
Chemical Reaction - MSN Encarta (1545 words)
A chemical reaction is a process that always results in the interconversion of chemical substances.
Chemical Reaction, process by which atoms or groups of atoms are redistributed, resulting in a change in the molecular composition of substances.
An example of a chemical reaction is formation of rust (iron oxide), which is produced when oxygen in the air reacts with iron.
CHEMICAL REACTION, (4617 words)
Chemical symbols and formulas are employed to describe chemical reactions; they denote substances having one set of formulas changing into substances having another set of formulas.
One kind of reaction, ion matching, is easy to understand as due to the pairing (or dissociation) of ions to form (or dissociate) neutral ionic substances, where a double arrow (instead of an equal sign) emphasizes the two possible directions of reaction.
Common examples of redox reactions involving oxygen are the rusting of metals such as iron (in which case the metals are oxidized by atmospheric oxygen), combustion, and the metabolic reactions associated with respiration.
  More results at FactBites »

 
 

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