chemical change

/ˌkɛməkəl tʃeɪndʒ/

Other forms: chemical changes

If you are waiting for some bananas to ripen, you are waiting for a chemical change. A chemical change occurs when a new substance is formed through a chemical reaction like when fruit ripens or rots.

When something undergoes a "chemical reaction" and a new substance is formed as a result, we call this chemical change. In some instances, simply applying heat can cause a chemical change. Cooking pancakes, for instance, is an example of a chemical change; the pancake batter "changes" from a liquid to a solid. Rust forming on metal is another example of a chemical change. The iron reacts with water and oxygen to create a new substance — rust.

Definitions of chemical change

1. noun

   (chemistry) any process determined by the atomic and molecular composition and structure of the substances involved
   synonyms: chemical action, chemical process

   types:

   acylation

   the process of introducing an acyl group into a compound

   agglutinating activity, agglutination

   the coalescing of small particles that are suspended in solution; these larger masses are then (usually) precipitated

   amylolysis

   conversion of starch to sugar

   association

   (chemistry) any process of combination (especially in solution) that depends on relatively weak chemical bonding

   blueing, bluing

   a process that makes something blue (or bluish)

   calcification

   a process that impregnates something with calcium (or calcium salts)

   catalysis, contact action

   acceleration of a chemical reaction induced the presence of material that is chemically unchanged at the end of the reaction

   chelation

   the process of forming a ring by forming one or more hydrogen bonds

   chemical reaction, reaction

   (chemistry) a process in which one or more substances are changed into others

   chlorination

   the addition or substitution of chlorine in organic compounds

   cleavage

   the breaking of a chemical bond in a molecule resulting in smaller molecules

   corroding, corrosion, erosion

   erosion by chemical action

   cracking

   the process whereby heavy molecules of naphtha or petroleum are broken down into hydrocarbons of lower molecular weight (especially in the oil-refining process)

   deamination, deaminization

   removal of the amino radical from an amino acid or other amino compound

   decalcification

   loss of calcium from bones or teeth

   decarboxylation

   the process of removing a carboxyl group from a chemical compound (usually replacing it with hydrogen)

   de-iodination

   the removal of iodine atoms from organic compounds

   demineralisation, demineralization

   the removal of minerals and mineral salts from a liquid (especially from water)

   desalination, desalinisation, desalinization

   the removal of salt (especially from sea water)

   digestion

   the process of decomposing organic matter (as in sewage) by bacteria or by chemical action or heat

   dissociation

   (chemistry) the temporary or reversible process in which a molecule or ion is broken down into smaller molecules or ions

   gasification

   the process of changing into gas

   gassing

   the process of interacting with gas

   hydrogenation

   a chemical process that adds hydrogen atoms to an unsaturated oil

   intumescence, intumescency, swelling

   the increase in volume of certain substances when they are heated (often accompanied by release of water)

   inversion

   a chemical process in which the direction of optical rotation of a substance is reversed from dextrorotatory to levorotary or vice versa

   iodination

   the substitution or addition of iodine atoms in organic compounds

   chemical mechanism, mechanism

   the atomic process that occurs during a chemical reaction

   nitrification

   the chemical process in which a nitro group is added to an organic compound (or substituted for another group in an organic compound)

   peptisation, peptization

   the process of converting to a sol; bringing to a colloidal solution

   photosynthesis

   synthesis of compounds with the aid of radiant energy (especially in plants)

   polymerisation, polymerization

   a chemical process that combines several monomers to form a polymer or polymeric compound

   precipitation

   the process of forming a chemical precipitate

   proteolysis

   the hydrolysis of proteins into peptides and amino acids by cleavage of their peptide bonds

   pyrochemical process, pyrochemistry

   processes for chemical reactions at high temperatures

   sequestration

   the action of forming a chelate or other stable compound with an ion or atom or molecule so that it is no longer available for reactions

   synaeresis, syneresis

   the separation of liquid from a gel that is caused by contraction (as in cheese making)

   synthesis

   the process of producing a chemical compound (usually by the union of simpler chemical compounds)

   transamination

   the process of transfering an amino group from one compound to another

   transamination

   the process of transposing an amino group within a chemical compound

   ferment, fermentation, fermenting, zymolysis, zymosis

   a process in which an agent causes an organic substance to break down into simpler substances; especially, the anaerobic breakdown of sugar into alcohol

   acetylation

   the process of introducing an acetyl group into a compound

   addition reaction

   a chemical reaction in which one molecule is added to another

   aldol reaction

   a reaction of aldehydes resulting in an aldol

   autocatalysis

   catalysis in which the catalyst is one of the products of the reaction

   biochemical mechanism

   a chemical mechanism involved in vital processes occurring in living organisms

   biogenesis, biosynthesis

   production of a chemical compound by a living organism

   bottom fermentation

   a slow kind of alcoholic fermentation at a temperature low enough that the yeast cells can sink to the bottom of the fermenting liquid; used in the production of lager

   chain reaction

   a series of chemical reactions in which the product of one is a reactant in the next

   chemical equilibrium, equilibrium

   a chemical reaction and its reverse proceed at equal rates

   chemosynthesis

   synthesis of carbohydrate from carbon dioxide and water; limited to certain bacteria and fungi

   chemical decomposition reaction, decomposition, decomposition reaction

   (chemistry) separation of a substance into two or more substances that may differ from each other and from the original substance

   displacement, displacement reaction

   (chemistry) a reaction in which an elementary substance displaces and sets free a constituent element from a compound

   double decomposition, double decomposition reaction, metathesis

   a chemical reaction between two compounds in which parts of each are interchanged to form two new compounds (AB+CD=AD+CB)

   elimination reaction

   a chemical reaction in which a molecule decomposes to two different molecules

   endothermic reaction

   a chemical reaction accompanied by the absorption of heat

   exothermic reaction

   a chemical reaction accompanied by the evolution of heat

   hydration

   the process of combining with water; usually reversible

   hydrocracking

   the process whereby hydrocarbon molecules of petroleum are broken down into kerosene and gasolene by the addition of hydrogen under high pressure in the presence of a catalyst

   hydrolysis

   a chemical reaction in which water reacts with a compound to produce other compounds; involves the splitting of a bond and the addition of the hydrogen cation and the hydroxide anion from the water

   neutralisation, neutralisation reaction, neutralization, neutralization reaction

   a chemical reaction in which an acid and a base interact with the formation of a salt; with strong acids and bases the essential reaction is the combination of hydrogen ions with hydroxyl ions to form water

   nucleosynthesis

   (astronomy) the cosmic synthesis of atoms more complex than the hydrogen atom

   ossification

   the calcification of soft tissue into a bonelike material

   oxidation, oxidisation, oxidization

   the process of oxidizing; the addition of oxygen to a compound with a loss of electrons; always occurs accompanied by reduction

   oxidation-reduction, oxidoreduction, redox

   a reversible chemical reaction in which one reaction is an oxidation and the reverse is a reduction

   photochemical reaction

   a chemical reaction produced by the action of light

   indentation, pitting, roughness

   the formation of small pits in a surface as a consequence of corrosion

   prechlorination

   chlorination prior to another chemical process

   reducing, reduction

   any process in which electrons are added to an atom or ion (as by removing oxygen or adding hydrogen); always occurs accompanied by oxidation of the reducing agent

   rust, rusting

   the formation of reddish-brown ferric oxides on iron by low-temperature oxidation in the presence of water

   saponification

   a chemical reaction in which an ester is heated with an alkali (especially the alkaline hydrolysis of a fat or oil to make soap)

   solvation

   a chemical process in which solvent molecules and molecules or ions of the solute combine to form a compound

   top fermentation

   a violent kind of alcoholic fermentation at a temperature high enough to carry the yeast cells to the top of the fermenting liquid; used in the production of ale

   vinification

   the process whereby fermentation changes grape juice into wine

   type of:

   action, activity, natural action, natural process

   a process existing in or produced by nature (rather than by the intent of human beings)