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Definition: chemical reaction from Dictionary of Energy

Chemistry. a chemical change in which the atoms or molecules of two or more substances are rearranged to form one or more additional substances, often having different properties.


chemical reaction

From The Columbia Encyclopedia
process by which one or more substances may be transformed into one or more new substances. Energy is released or is absorbed, but no loss in total molecular weight occurs. When, for example, water is decomposed, its molecules, each of which consists of one atom of oxygen and two of hydrogen, are broken down; the hydrogen atoms then combine in pairs to form hydrogen molecules and the oxygen atoms to form oxygen molecules. In a chemical reaction, substances lose their characteristic properties. Water, for example, a liquid which neither burns nor supports combustion, is decomposed to yield flammable hydrogen and combustion-supporting oxygen. In some reactions heat is given off (exothermic reactions), and in others heat is absorbed (endothermic reactions). Furthermore, the new substances formed differ from the original substances in the energy they contain. Chemical reactions are classified according to the kind of change that takes place. When a compound, which consists of two or more…
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Full text Article chemical reaction

From Philip's Encyclopedia
Calorimeters measure the amount of heat absorbed...
Change or process in which chemical substances convert into other substances. This involves the breaking and formation of chemical bonds. Reaction mechanisms include endothermic, exothermic, replacement, combination, decomposition and oxidation reactions. …
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Full text Article chemical reaction

From The Columbia Encyclopedia
process by which one or more substances may be transformed into one or more new substances. Energy is released or is absorbed, but no loss in total molecular weight occurs. When, for example, water is decomposed, its molecules, each of which consists of one atom of oxygen and two of hydrogen, are…
| 341 words
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Full text Article chemical reaction

From Hawley's Condensed Chemical Dictionary
A chemical change that may occur in several ways, e.g., combination, replacement, by decomposition, or by some modification of these. Reactions are endothermic when heat is needed to maintain them and exothermic when they evolve heat. All chemical reactions are in balance; i.e., the numbers of atoms…
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Full text Article chemical reaction

From Britannica Concise Encyclopedia
Any chemical process in which substances are changed into different ones, with different properties, as distinct from changing position or form ( phase ). Chemical reactions involve the rupture or rearrangement of the bonds holding atom s together ( see bonding ), never atomic nuclei. The total mass…
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Full text Article chemical reaction

From Science Encyclopedia: Encyclopedia of Chemistry
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Full text Article chemical reaction

From The Penguin Dictionary of Science
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Full text Article chemical reaction

From The Macquarie Dictionary
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Full text Article Chemical Reaction

From Dictionary of Industrial Terms
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Full text Article chemical reaction

From Dictionary of Energy
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Full text Article chemical reaction

From Collins English Dictionary
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