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- The separation of a chemical compound into elements or simpler compounds. It is sometimes defined as the exact opposite of a chemical synthesis. Chemical decomposition is often an undesired chemical reaction. The stability that a chemical compound ordinarily has is eventually limited when exposed to extreme environmental conditions like heat, radiation, humidity or the acidity of a solvent. The details of decomposition processes are generally not well defined, as a molecule may break up into a host of smaller fragments. Chemical decomposition is exploited in several analytical techniques, notably mass spectrometry, traditional gravimetric analysis, and thermogravimetric analysis.
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| Abstract from DBPedia | Chemical decomposition, or chemical breakdown, is the process or effect of simplifying a single chemical entity (normal molecule, reaction intermediate, etc.) into two or more fragments. Chemical decomposition is usually regarded and defined as the exact opposite of chemical synthesis. In short, the chemical reaction in which two or more products are formed from a single reactant is called a decomposition reaction. The details of a decomposition process are not always well defined but some of the process is understood; much energy is needed to break bonds. Since all decomposition reactions break apart the bonds holding it together in order to produce into its simpler basic parts, the reactions would require some form of this energy in varying degrees. Because of this fundamental rule, it is known that most of these reactions are endothermic although exceptions do exist. The stability of a chemical compound is eventually limited when exposed to extreme environmental conditions such as heat, radiation, humidity, or the acidity of a solvent. Because of this chemical decomposition is often an undesired chemical reaction. However chemical decomposition is being used in a growing number of ways. For example this method is employed for several analytical techniques, notably mass spectrometry, traditional gravimetric analysis, and thermogravimetric analysis. Additionally decomposition reactions are used today for a number of other reasons in the production of a wide variety of products. One of these is the explosive breakdown reaction of sodium azide [(NaN3)2] into nitrogen gas (N2) and sodium (Na). It is this process which powers the life-saving airbags present in virtually all of today's automobiles. Decomposition reactions can be generally classed into three categories; thermal, electrolytic, and photolytic decomposition reactions.化学分解（かがくぶんかい、Chemical decomposition）は、化合物が2種以上の簡単な物質に変化する化学反応である。単に分解〈ぶんかい、decomposition〉という場合も多い。反応様式で分解の逆の構成となる化学反応は化学合成（化合）または合成と呼ばれる。 具体的には高温による熱分解や、光や放射線による光分解や放射線分解が代表的な分解である。 水の例を以下に示す。水は、電気分解によって水素分子と酸素分子に分解することができる。 2H2O → 2H2 + O2 過酸化水素は放置すると水と酸素に分解する。 2H2O2 → 2H2O + O2 反応様式で分解と逆反応とが可逆的に起こる状態は解離と呼ばれる。また、化合物が順次低分子量の物質に順次分解してゆく過程は日本語では減成〈げんせい、decomposition〉と呼ばれる。 (Source: http://dbpedia.org/resource/Chemical_decomposition) |
