ⓘ Chemical reactions ..

Acid hydrolysis

In organic chemistry, acid hydrolysis is a process in which a protic acid is used to catalyze the cleavage of a chemical bond via a nucleophilic substitution reaction, with the addition of the elements of water. For example, in the conversion of cellulose or starch to glucose. For the case of esters and amides, it can be defined as an acid catalyzed nucleophilic acyl substitution reaction. The term is also applied to certain nucleophilic addition reactions, such as in the acid catalyzed hydrolysis of nitriles to amides. Acid hydrolysis does not usually refer to the acid catalyzed addition ...

Addition reaction

An addition reaction, in organic chemistry, is in its simplest terms an organic reaction where two or more molecules combine to form a larger one. Addition reactions are limited to chemical compounds that have multiple bonds, such as molecules with carbon–carbon double bonds alkenes, or with triple bonds alkynes. Molecules containing carbon - hetero double bonds like carbonyl C=O groups, or imine C=N groups, can undergo addition, as they too have double-bond character. An addition reaction is the reverse of an elimination reaction. For instance, the hydration of an alkene to an alcohol is ...

Adduct

An adduct is a product of a direct addition of two or more distinct molecules, resulting in a single reaction product containing all atoms of all components. The resultant is considered a distinct molecular species. Examples include the addition of sodium bisulfite to an aldehyde to give a sulfonate. It can just be considered as a single product resulting from direct addition of different molecules and constitutes all the reactant molecules atoms. Adducts often form between Lewis acids and Lewis bases. A good example is the formation of adducts between the Lewis acid borane and the oxygen ...

Adduct purification

Adduct purification is a technique for preparing extremely pure simple organometallic compounds, which are generally unstable and hard to handle, by purifying a stable adduct with a Lewis acid and then obtaining the desired product from the pure adduct by thermal decomposition. Epichem Limited is the licensee of the major patents in this field, and uses the trademark EpiPure to refer to adduct-purified materials; Professor Anthony Jones at Liverpool University is the initiator of the field and author of many of the important papers. The choice of Lewis acid and of reaction medium is import ...

Air–fuel ratio

Air–fuel ratio is the mass ratio of air to a solid, liquid, or gaseous fuel present in a combustion process. The combustion may take place in a controlled manner such as in an internal combustion engine or industrial furnace, or may result in an explosion. The air-fuel ratio determines whether a mixture is combustible at all, how much energy is being released, and how much unwanted pollutants are produced in the reaction. Typically a range of fuel to air ratios exists, outside of which ignition will not occur. These are known as the lower and upper explosive limits. In an internal combusti ...

Alkali–aggregate reaction

Alkali–aggregate reaction is a term mainly referring to a reaction which occurs over time in concrete between the highly alkaline cement paste and non-crystalline silicon dioxide, which is found in many common aggregates. This reaction can cause expansion of the altered aggregate, leading to spalling and loss of strength of the concrete.

                                     

ⓘ Chemical reactions

  • chemical reaction has been extended to reactions between entities smaller than atoms, including nuclear reactions radioactive decays, and reactions between
  • extent to which reactions occur. In a reversible reaction chemical equilibrium is reached when the rates of the forward and reverse reactions are equal the
  • which was held in Amsterdam in 1957. Chemical reaction engineering aims at studying and optimizing chemical reactions in order to define the best reactor
  • chemistry, a reaction mechanism is the step by step sequence of elementary reactions by which overall chemical change occurs. A chemical mechanism is
  • chemical reaction Most chemical reactions are stepwise, that is they take more than one elementary step to complete. An intermediate is the reaction
  • all decomposition reactions break apart the bonds holding it together in order to produce into its simpler basic parts, the reactions would require some
  • A chemical clock or clock reaction is a complex mixture of reacting chemical compounds in which the onset of an observable property occurs after a predictable
  • processes are called chemical reactions and, in general, are not reversible except by further chemical reactions Some reactions produce heat and are
  • Organic reactions are chemical reactions involving organic compounds. The basic organic chemistry reaction types are addition reactions elimination reactions
  • Chemical synthesis is the artificial execution of useful chemical reactions to obtain one or several products. This occurs by physical and chemical manipulations
  • Chemical thermodynamics is the study of the interrelation of heat and work with chemical reactions or with physical changes of state within the confines