A chemical reaction is a process that always results in the interconversion of chemical substances. A chemical substance is a Material with a definite chemical composition. ^[1] The substance or substances initially involved in a chemical reaction are called reactants. A reagent or reactant is a substance or compound consumed during a Chemical reaction. Chemical reactions are usually characterized by a chemical change, and they yield one or more products which are, in general, different from the reactants. Is a process in which Reactants are changed into one or more different products. A product is a substance that forms as a result of a Biological - or Chemical reaction. 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. The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J A chemical bond is the physical process responsible for the attractive interactions between Atoms and Molecules and which confers stability to diatomic and polyatomic A chemical equation is a symbolic representation of a Chemical reaction. Motivation and history When calculating Scattering cross sections in Particle physics, the interaction between particles can be described In Nuclear physics, a nuclear reaction is the 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 Chemistry, chemical synthesis is purposeful execution of Chemical reactions in order to get a product, or several products 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. Biochemistry is the study of the chemical processes in living Organisms It deals with the Structure and function of cellular components such as Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as a catalyst Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins In Biochemistry, a metabolic pathway is a series of chemical reactions occurring within a cell.

Contents 1 Reaction types 2 Chemical kinetics 3 See also 4 References

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. This page aims to list well-known reactions and Reagents in Organic chemistry. Below are examples of widely used terms for describing common kinds of reactions.

• Isomerisation, in which a chemical compound undergoes a structural rearrangement without any change in its net atomic composition; see stereoisomerism
• Direct combination or synthesis, in which 2 or more chemical elements or compounds unite to form a more complex product:

N₂ + 3 H₂ → 2 NH₃

• Chemical decomposition or analysis, in which a compound is decomposed into smaller compounds or elements:

2 H₂O → 2 H₂ + O₂

• Single displacement or substitution, characterized by an element being displaced out of a compound by a more reactive element:

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. In Chemistry isomerisation is the process by which one Molecule is transformed into another molecule which has exactly the same atoms but the atoms are rearranged Stereoisomers are isomeric molecules that have the same molecular formula and sequence of bonded atoms (constitution but which differ in the three dimensional orientations A Combination Reaction or a Synthesis Reaction is a general category of a Chemical reaction (the term usually refers to an Inorganic chemical reaction) In Chemistry, chemical synthesis is purposeful execution of Chemical reactions in order to get a product, or several products Nitrogen (ˈnaɪtɹəʤɪn is a Chemical element that has the symbol N and Atomic number 7 and Atomic weight 14 Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Ammonia is a compound with the formula N[[hydrogen H3]] It is normally encountered as a Gas with a characteristic pungent Odor Chemical decomposition or analysis is the separation of a Chemical compound into elements or smaller compounds Water is a common Chemical substance that is essential for the survival of all known forms of Life. Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the A single-displacement reaction, also called single-replacement reaction, is when an element or ion moves out of one compound and into another In a substitution reaction, a Functional group in a particular Chemical compound is replaced by another group In Chemistry, the reactivity series is a series of Metals in order of reactivity from highest to lowest Sodium (ˈsoʊdiəm is an element which has the symbol Na( Latin natrium, from Arabic natrun) atomic number 11 atomic mass 22 For sodium chloride in the diet see Salt. Sodium chloride, also known as common salt, table salt, or Halite, is a 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 An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge Silver nitrate also known as lunar caustic is a soluble Chemical compound with Chemical formula Ag[[Nitrogen N]] O 3 Sodium nitrate is the Chemical compound with the formula NaNO3 Silver chloride is a Chemical compound with the Chemical formula Ag[[Chlorine Cl]] In Computer science, ACID ( Atomicity Consistency Isolation Durability) is a set of properties that guarantee that Database transactions are In Chemistry, a base is most commonly thought of as an aqueous substance that can accept Protons This refers to the Brønsted-Lowry theory of acids and 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. Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state The oxidation number of a central atom in a coordination compound is the charge that it would have if all the Ligands were removed along with the Electron pairs 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 S₂O₃^2- (thiosulfate anion) is oxidized to S₄O₆^2-. Thiosulfate (S2O32&minus is an Oxyanion of Sulfur produced by the reaction of Sulfite ions with elemental sulfur

• 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. Combustion or burning is a complex sequence of Exothermic chemical reactions between a Fuel and an Oxidant accompanied by the production of 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 F₂ → CF₄ + 2 HF + SF₆

Organic reactions encompass a wide assortment of reactions involving compounds which have carbon as the main element in their molecular structure. Fluorine, fluorum meaning "to flow" is the Chemical element with the symbol F and Atomic number 9 Tetrafluoromethane, also known as carbon tetrafluoride, Freon-14 and R 14, is a Carbon Fluoride (CF4 Structure HF forms orthorhombic crystals consisting of zig-zag chains of HF molecules Sulfur hexafluoride is an Inorganic compound with the formula. Organic reactions are Chemical reactions involving Organic compounds The basic Organic chemistry reaction types are Addition reactions Elimination An organic compound is any member of a large class of Chemical compounds whose Molecules contain Carbon. Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 The reactions in which an organic compound may take part are largely defined by its functional groups. In Organic chemistry, functional groups are specific groups of Atoms within Molecules that are responsible for the characteristic Chemical reactions Defined in opposition to inorganic reactions. Reactions can also be classified according to their mechanism, some typical examples being:

• Reactions of ions, e. g. disproportionation of hypochlorite
• Reactions with reactive ionic intermediates, e. Disproportionation or dismutation is used to describe two particular types of chemical reaction A chemical reaction of the type 2A → A' + A" where The hypochlorite Ion is Cl[[Oxygen O]]− A hypochlorite compound is a Chemical compound containing this group with chlorine in Oxidation g. reactions of enolates
• Radical reactions, e. Enols (also known as alkenols) are Alkenes with a Hydroxyl group affixed to one of the carbon atoms composing the Double bond. In Chemistry, radicals (often referred to as free radicals) are atoms molecules or ions with Unpaired electrons on an otherwise Open shell g. combustion at high temperature
• Reactions of carbenes

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. In Chemistry, a carbene is a highly reactive Organic molecule containing a Carbon atom with six valence electrons and having the general formula Chemical kinetics, also known as reaction kinetics is the study of rates of chemical processes The reaction rate or rate of reaction for a Reactant or product in a particular reaction is intuitively defined as how fast a reaction takes In Chemistry, concentration is the measure of how much of a given substance there is mixed with another substance Pressure (symbol 'p' is the force per unit Area applied to an object in a direction perpendicular to the surface Analysis of reaction rates is important for several applications, such as in chemical engineering or in chemical equilibrium study. Chemical engineering is the branch of Engineering that deals with the application of Physical science (e In a Chemical process, chemical equilibrium is the state in which the chemical activities or Concentrations of the reactants and products have no net change Rates of reaction depends basically on:

• 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. A reagent or reactant is a substance or compound consumed during a Chemical reaction. Surface area is the measure of how much exposed Area an object has Larger surface area leads to higher reaction rates.
• Pressure, by increasing the pressure, you decrease the volume between molecules. Pressure (symbol 'p' is the force per unit Area applied to an object in a direction perpendicular to the surface 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. In Chemistry, activation energy, also called midnight energy, is a term introduced in 1889 by the Swedish scientist Svante Arrhenius, that is defined 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. Temperature is a physical property of a system that underlies the common notions of hot and cold something that is hotter generally has the greater temperature Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as 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. In Chemistry, activation energy, also called midnight energy, is a term introduced in 1889 by the Swedish scientist Svante Arrhenius, that is defined 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. Electromagnetic radiation takes the form of self-propagating Waves in a Vacuum or in Matter. Ultraviolet ( UV) light is Electromagnetic radiation with a Wavelength shorter than that of Visible light, but longer than X-rays This is particularly true for reactions involving radicals. In Chemistry, radicals (often referred to as free radicals) are atoms molecules or ions with Unpaired electrons on an otherwise Open shell

Reaction rates are related to the concentrations of substances involved in reactions, as quantified by the rate law of each reaction. In Chemistry, concentration is the measure of how much of a given substance there is mixed with another substance The rate law or rate equation for a Chemical reaction is an equation which links the Reaction rate with concentrations or pressures of reactants and constant Note that some reactions have rates that are independent of reactant concentrations. These are called zero order reactions. The rate law or rate equation for a Chemical reaction is an equation which links the Reaction rate with concentrations or pressures of reactants and constant

See also

• List of reactions
• Organic reaction
• Inorganic chemical reaction
• List of important publications in chemistry
• Stoichiometry
• Stoichiometric coefficient
• Transition state theory
• Gas stoichiometry
• Thermodynamic databases for pure substances
• Autocatalytic reaction
• Coefficients

References

1. ^ International Union of Pure and Applied Chemistry. This page aims to list well-known reactions and Reagents in Organic chemistry. Organic reactions are Chemical reactions involving Organic compounds The basic Organic chemistry reaction types are Addition reactions Elimination Some criteria for editing this page have been debated and are displayed Stoichiometry (sometimes called reaction stoichiometry to distinguish it from composition stoichiometry is the Calculation of Quantitative (measurable Stoichiometry (sometimes called reaction stoichiometry to distinguish it from composition stoichiometry is the Calculation of Quantitative (measurable In Chemistry, transition state theory is a conception of Chemical reactions or other processes involving rearrangement of matter as proceeding through a continuous Stoichiometry (sometimes called reaction stoichiometry to distinguish it from composition stoichiometry is the Calculation of Quantitative (measurable Thermodynamic databases contain information about thermodynamic properties for substances the most important being Enthalpy, Entropy, and Autocatalytic reactions are Chemical reactions in which at least one of the products is also a Reactant. In Mathematics, a coefficient is a Constant multiplicative factor of a certain object The International Union of Pure and Applied Chemistry ( IUPAC) (aɪjuːpæk or ay-yoo-pec) is an international Non-governmental organization "chemical reaction". Compendium of Chemical Terminology Internet edition. Compendium of Chemical Terminology (ISBN 0-86542-684-8 is a book published by IUPAC containing internationally accepted definitions for terms in Chemistry.

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