chemical reaction

A chemical reaction is when a substance (or a few substances) change into another substance. Chemical reactions are chemical transformations.

If you take a chemistry class, you'll definitely learn about chemical reactions: when one or more substances change into something else. When making beer, yeast turns the sugar into alcohol: that's a chemical reaction. When something iron rusts because of exposure to air, that's a chemical reaction. There are many types of chemical reactions, but they all involve transformations or changes. Water boiling — becoming a gas — is not a chemical reaction, since the steam is still water; the substance didn’t change.

Definitions of chemical reaction
  1. noun
    (chemistry) a process in which one or more substances are changed into others
    “there was a chemical reaction of the lime with the ground water”
    synonyms: reaction
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    types:
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    addition reaction
    a chemical reaction in which one molecule is added to another
    aldol reaction
    a reaction of aldehydes resulting in an aldol
    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
    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
    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
    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
    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
    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)
    acid-base balance, acid-base equilibrium
    (physiology) the normal equilibrium between acids and alkalis in the body
    calcination
    the conversion of metals into their oxides as a result of heating to a high temperature
    burning, combustion
    a process in which a substance reacts with oxygen to give heat and light
    double replacement reaction
    a chemical reaction between two compounds where the positive ion of one compound is exchanged with the positive ion of another compound
    electrolysis
    (chemistry) a chemical decomposition reaction produced by passing an electric current through a solution containing ions
    light reaction
    the first stage of photosynthesis during which energy from light is used for the production of ATP
    nitrification
    the oxidation of ammonium compounds in dead organic material into nitrates and nitrites by soil bacteria (making nitrogen available to plants)
    rust, rusting
    the formation of reddish-brown ferric oxides on iron by low-temperature oxidation in the presence of water
    type of:
    chemical action, chemical change, chemical process
    (chemistry) any process determined by the atomic and molecular composition and structure of the substances involved
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