- 関
- endothermal reaction
WordNet
- (mechanics) the equal and opposite force that is produced when any force is applied to a body; "every action has an equal and opposite reaction"
- a response that reveals a persons feelings or attitude; "he was pleased by the audiences reaction to his performance"; "John feared his mothers reaction when she saw the broken lamp"
- a bodily process occurring due to the effect of some antecedent stimulus or agent; "a bad reaction to the medicine"; "his responses have slowed with age" (同)response
- doing something in opposition to another way of doing it that you dont like; "his style of painting was a reaction against cubism"
- an idea evoked by some experience; "his reaction to the news was to start planning what to do"
- extreme conservatism in political or social matters; "the forces of reaction carried the election"
- (of a chemical reaction or compound) occurring or formed with absorption of heat (同)endothermal, heat-absorbing
PrepTutorEJDIC
- {名}(…に対する)『反応』《+『to』+『名』》 / 〈U〉(…に対する)(政治的・社会的な)『反動』,逆コース《+『against』+『名』》 / 〈U〉〈C〉化学反応,化学変化 / 〈U〉〈C〉(物理学で)反作用
- (化学反応が)吸熱性の,吸熱反応の
Wikipedia preview
出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2013/01/04 16:48:16」(JST)
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This article is about the physical effect. For self-maintained thermal homeostasis, see Endotherm.
In thermodynamics, the word endothermic describes a process or reaction in which the system absorbs energy from its surroundings in the form of heat. It is a modern coinage from Greek roots. The prefix endo- derives from the Greek word "endon" (ἔνδον) meaning "within," and the latter part of the word comes from the Greek word root "therm" (θερμ-) meaning "hot." The intended sense is that of a reaction that depends on taking in heat if it is to proceed. The opposite of an endothermic process is an exothermic process, one that releases, "gives out" energy in the form of heat. Thus in each term (endothermic & exothermic) the prefix refers to where heat goes as the reaction occurs. The term endothermic was coined by Marcellin Berthelot (25 October 1827 – 18 March 1907).
The concept is frequently applied in physical sciences to, for example, chemical reactions, where thermal energy (heat) is converted to chemical bond energy.
Contents
- 1 Implications for chemical reactions
- 2 Contrast between thermodynamic and biological terminology
- 3 Examples
- 4 See also
- 5 References
- 6 External links
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Implications for chemical reactions
Chemical endothermic reactions need heat to be performed. In a thermochemical reaction that is endothermic, the heat is placed on the reactants' side (heat is necessary for and absorbed during the reaction). The heat absorbed during the chemical reaction results in a decrease in temperature of its surroundings. This principle is employed in instant cold compresses (ice packs) which are used in first-aid.
Contrast between thermodynamic and biological terminology
Note that because of historical accident, students encounter a possible source of confusion between the terminology of physics and biology. Whereas the thermodynamic terms "exothermic" and "endothermic" respectively refer to processes that give out heat energy and processes that absorb heat energy, in biology the sense is effectively inverted. The metabolic terms "ectothermic" and "endothermic" respectively refer to organisms that rely largely on external heat to achieve a full working temperature, and to organisms that produce heat from within as a major factor in controlling their bodily temperature.
Examples
- Photosynthesis
- Melting ice
- Thermal decomposition reactions
- Forming a cation from an atom in the gas phase
- Dissolving ammonium chloride in water
- High-energy neutrons can also produce tritium from lithium-7 in an endothermic reaction, consuming 2.466 MeV. This was discovered when the 1954 Castle Bravo nuclear test produced an unexpectedly high yield.[1]
-
7
3Li |
+ |
n |
→ |
4
2He |
+ |
3
1T |
+ |
n |
See also
- Endergonic
- Exothermic
- Exergonic
- Exergonic reaction
References
- ^ Hisham Zerriffi (January 1996). "Tritium: The environmental, health, budgetary, and strategic effects of the Department of Energy's decision to produce tritium". Institute for Energy and Environmental Research. http://www.ieer.org/reports/tritium.html#(11). Retrieved 2010-09-15.
External links
- Endothermic Definition - MSDS Hyper-Glossary
UpToDate Contents
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English Journal
- Synthesis and applications of eco-magnetic nano-hydroxyapatite chitosan composite for enhanced fluoride sorption.
- Pandi K1, Viswanathan N2.
- Carbohydrate polymers.Carbohydr Polym.2015 Dec 10;134:732-9. doi: 10.1016/j.carbpol.2015.08.003. Epub 2015 Aug 6.
- Adsorption is a significant reaction occurs between adsorbent/water interface for controlling the pollutants in the aqueous environment. In this regard, an eco-magnetic biosorbent was prepared by uniform deposition of magnetic Fe3O4 particles on the surface of nano-hydroxyapatite (n-HAp)/chitosan (C
- PMID 26428179
- Dynamics of the F- + CH3I → HF + CH2I- Proton Transfer Reaction.
- Zhang J, Xie J, Hase WL.
- The journal of physical chemistry. A.J Phys Chem A.2015 Oct 16. [Epub ahead of print]
- Direct chemical dynamics simulations, at collision energies Erel of 0.32 and 1.53 eV, were performed to obtain an atomistic understanding of the F- + CH3I reaction dynamics. There is only the F- + CH3I → CH3F + I- bimolecular nucleophilic substitution SN2 product channel at 0.32 eV. Increasing Ere
- PMID 26473337
- Reactions of Th+ + H2, D2, and HD Studied by Guided Ion Beam Tandem Mass Spectrometry and Quantum Chemical Calculations.
- Cox RM1, Armentrout PB1, de Jong WA2.
- The journal of physical chemistry. B.J Phys Chem B.2015 Oct 6. [Epub ahead of print]
- Kinetic energy dependent reactions of Th+ with H2, D2, and HD were studied using a guided ion beam tandem mass spectrometer. Formation of ThH+ and ThD+ is endothermic in all cases with similar thresholds. Branching ratio results for the reaction with HD indicate that Th+ reacts via a statistical mec
- PMID 26414691
Japanese Journal
- Preparation and characterization of chitosan–caboxymethyl-β-cyclodextrin entrapped nanozero-valent iron composite for Cu (II) and Cr (IV) removal from wastewater
- Sikder Md. Tajuddin,Mihara Yoshihiro,Islam Md. Shariful,Saito Takeshi,Tanaka Shunitz,Kurasaki Masaaki
- Chemical Engineering Journal 236, 378-387, 2014-01-15
- … The rate of reduction can be expressed by pseudo-second-order reaction kinetics. … The rate constants increased with increasing iron loading and initial concentration at pH 6, while the adsorption of Cr (VI) and Cu (II) was found to be endothermic and exothermic, respectively. …
- NAID 120005346990
- Morphology control of beta-SiAlON via salt-assisted combustion synthesis
- Niu Jing,Harada Kazuto,Nakatsugawa Isao,Akiyama Tomohiro
- Ceramics international 40(1), 1815-1820, 2014-01
- … A facile salt-assisted combustion synthesis of beta-SiAlON and systematic characterization of the endothermic effects of addition of KCl, MgCl2, and CaCl2 were investigated under a nitrogen pressure of 1 MPa. … The results indicated that the metal chlorides act as perfect diluents that effectively absorb the reaction heat via their melting and evaporation, which occur in the same temperature ranges as the two stages of the exothermic processes. …
- NAID 120005418080
- Measurements of Temperature and Gas Generation during Fast Pyrolysis of Single Biomass Particle
- MURATA Shoma,IRII Toshihide,TANOUE Ken-ichiro,NISHIMURA Tatsuo,UEMURA Yoshimitsu,TANIGUCHI Miki,SASAUCHI Ken-ichi
- 日本エネルギー学会誌 93(9), 931-935, 2014
- … From the time courses of the temperature at the center TC of a cornel particle, there could be two regions due to the endothermic reactions of biomass during pyrolysis and exothermic char formation from tar. … Between these two regions, the endothermic reactions of biomass during pyrolysis could be completed at about 690 K. … 773 K due to both the endothermic reactions of biomass during pyrolysis and the decomposition of generated tar. …
- NAID 130004696854
Related Links
- A chemical demonstration showing that some reactions absorb heat. Carleton University, Ottawa, Canada. ... Sign in with your Google Account (YouTube, Google+, Gmail, Orkut, Picasa, or Chrome) to add Bob Burk 's ...
- This is a list of chemical reactions that are endothermic reactions. ... An endothermic reaction is any chemical reaction that absorbs heat from its environment. Here's a list of examples of endothermic reactions. You can use these ...
Related Pictures
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- endothermic reaction、endothermal reaction
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- endothermic reaction
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- react、respond、response、responsive
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- endothermal