Endothermic gas is the gaseous product of incomplete combustion in a controlled environment with a composition of hydrogen gas H sub 2 sub , nitrogen gas N sub 2 sub , and carbon monoxide CO . Hydrogen and carbon monoxide are reducing agents, so they shield surfaces from oxidation . physical chemistry stub Category Gases ... more details
For Exergonic and Endergonic reactions , see the separate articles Endergonic reaction Exergonic reaction See also Exergonic Endergonic Exothermic Endothermic Disambig ... more details
. In contrast, when endothermic reactions occur, energy is absorbed to place an electron in a higher ... complex. The loss of energy within solution is absorbed by the endothermic reaction and therefore is a loss of heat. This is the physical understanding of exothermic and endothermic reactions within solution ... 101 thermo faq exothermic endothermic examples.shtml Exothermic Endothermic examples ref Condensation ..., endothermic reaction s. In a thermochemical reaction that is exothermic, the heat may be listed ... the terminology of physics and biology. Whereas the thermodynamic terms exothermic and endothermic respectively ... Endergonic reaction Exergonic Exergonic reaction Endothermic reaction References references External ... more details
The enthalpy of mixing also called heat of mixing is the heat thermodynamics heat that is taken up or released upon mixing of two non reactive chemical substances. When the enthalpy of mixing is positive, mixing is endothermic while negative enthalpy of mixing signifies exothermic mixing. A well known approximation for calculating the heat of mixing is Flory Huggins solution theory . See also Enthalpy change of solution Category Enthalpy Category Thermodynamics de Mischungsw rme ... more details
Unreferenced date May 2009 Merge to Endergonic reaction date January 2012 Endergonic from the prefix endo , derived from the Greek word endon , within , and the Greek word ergon , work thermodynamics work means absorbing energy in the form of work. Endergonic reactions are not spontaneous. By thermodynamic standards, positive work, a form of energy , is defined as moving from the wikt surroundings surroundings the external region to the system the internal region . Thus, an endergonic process, as contrasted with an exergonic process, is one wherein the system absorbs energy from the surroundings. As a result, during an endergonic process, energy is put into the system. If the transformation occurs at constant pressure and temperature, G 0 . An endergonic reaction is a chemical reaction that absorbs energy in the form of work. A good example of a net endergonic process is photosynthesis . Also, in metabolism , an endergonic process is anabolic , meaning, that energy is stored. In metabolism, catabolic and anabolic processes are coupled by Adenosine triphosphate ATP . See also col begin col break Exergonic Exergonic reaction Exothermic Endothermic col break Exothermic reaction Endothermic reaction Warm blooded Endotherm Warm blooded Exotherm col end Category Thermodynamics Category Chemical thermodynamics ar hu Endergonikus reakci nl Endergoon ... more details
One source date May 2009 Wiktionary exergonic Exergonic from the suffix exo , derived for the Greek word ex , outside and the suffix ergonic, derived from the Greek word ergon , work thermodynamics work means releasing energy in the form of work . In thermodynamics, work is defined as the energy moving from the system the internal region to the surroundings the external region during a given process. An exergonic process is one in which there is a positive flow of energy from the system to the surroundings. This is in contrast with an endergonic process. ref GoldBookRef title exergonic exoergic reaction file E02262 ref Constant pressure, constant temperature reactions are exergonic iff the Gibbs free energy is negative G 0 . All physical and chemical systems in the universe follow the second law of thermodynamics and proceed in a downhill, i.e., exergonic , direction. Thus, left to itself, any physical or chemical system will proceed, according to the second law of thermodynamics , in a direction that tends to lower the thermodynamic free energy free energy of the system, and thus to expend energy in the form of work. These reactions occur spontaneously. See also col begin col break Endergonic Endergonic reaction Exothermic Endothermic Exergonic reaction col break Exothermic reaction Endothermic reaction Warm blooded Endotherm Warm blooded Exotherm col end References Reflist Category Thermodynamics Category Chemical thermodynamics de Exergone und endergone Reaktion fr R action exergonique hu Exergonikus reakci nl Exergoon pt Exerg nica ... more details
The enthalpy of solution , enthalpy of dissolution , or heat of solution is the enthalpy change associated with the dissolution of a substance in a solvent at constant pressure resulting in infinite dilution. The enthalpy of solution is most often expressed in Joule kJ mole unit mol at constant temperature. The energy change can be regarded as being made of three parts, the endothermic breaking of bonds within the solute and within the solvent, and the formation of attractions between the solute and the solvent. Energetics Dissolution of most gases is exothermic. That is, when a gas dissolves in a liquid solvent, energy is released as heat, warming both the system i.e. the solution and the surroundings. The temperature of the solution then decreases to that of the surroundings. The equilibrium, between the gas as a separate phase and the gas in solution, will therefore by Le Ch telier s principle shift to favour the gas going into solution as the temperature is decreased. Thus, decreasing the temperature increases the solubility of a gas. When a saturated solution of a gas is heated, gas comes out of solution. Steps in dissolution Dissolution can be viewed as occurring in three steps Breaking solute solute attractions endothermic , see for instance lattice energy in salts. Breaking solvent solvent attractions endothermic , for instance that of hydrogen bonding Forming solvent solute attractions exothermic , in solvation . The value of the enthalpy of solution is the sum of these individual steps. Dissolving ammonium nitrate in water is endothermic. The energy released by solvation of the ammonium ions and nitrate ions is less that the energy absorbed in breaking up the ammonium nitrate ionic lattice and the attractions between water molecules. Dissolving potassium hydroxide is exothermic, as more energy is released during solvation than is used in breaking up the solute and solvent. The enthalpy of solution of an ideal solution is zero since the attractive and repul ... more details
File Activation energy.svg thumb 400px right An energy profile, showing the products Y , reactants X , activation energy E sub a sub for the endothermic and exothermic reaction, and the enthalpy H . The profile for same reaction but with a catalyst is also shown. An Energy profile , or reaction profile is a schematic plot of the energy of a reacting system as a function of the reaction coordinate . The term energy may refer to enthalpy , free energy or internal energy. Energy profiles are intended to illustrate the energies of reactant, intermediate, transition and product states of the system in the order in which they are formed they are useful for depicting reaction mechanism reaction mechanisms . ref http www.iupac.org reports 1999 7110minkin e.html International Union of Pure and Applied Chemistry ref References reflist reaction stub Category Chemical reactions sr ... more details
The BMA process ref The name is abbreviated from B laus ure hydrogen cyanide from M ethan methane and A mmoniak ammonia in German. ref or Degussa process is a chemical process developed by the German chemical company Degussa ref http www.patentstorm.us patents 5928984 description.html patent literature ref for the production of hydrogen cyanide from methane and ammonia in presence of a platinum Catalysis catalyst . Hydrogen cyanide is used in the chemical industry for the production of intermediate chemicals like acrylonitrile , methyl methacrylate , and adiponitrile . The reaction equation is analog to the Steam reforming steam methane reforming SMR reaction of methane and water CH sub 4 sub NH sub 3 sub &rarr HCN 3 H sub 2 sub , &Delta H sub R sub 251 kJ mol The reaction is extremely endothermic . The reactants react in a Platinum covered pipe at approximately 1400 C. The reaction mixture contains around 23 Vol. HCN and 72 Vol. H sub 2 sub as well as minor quantities of ammonia, nitrogen, and unreacted methane. ref cite journal title Die technische Synthese von Cyanwasserstoff aus Methan und Ammoniak ohne Zusatz von Sauerstoff author F. Endter journal Chemie Ingenieur Technik year 1958 volume 30 issue 5 pages 281 376 doi 10.1002 cite.330300506 ref The gaseous mixture is introduced in a scrubber and treated with an ammonia solution to separate the acidic HCN from other gaseous components H sub 2 sub , CH sub 4 sub , and N sub 2 sub . In a second step the HCN is released by acidification of the solution, followed by a final distillation of the hydrogen cyanide. Because of the highly endothermic reaction, the BMA process is of lower importance for the production of HCN compared to the Andrussow oxidation . References references External links http www.methacrylates.de methacrylates MCMSbase Templates WWWTemplate.aspx?NRMODE Published&NRNODEGUID 7b855AEA74 FFCC 4FE6 991E FE45567D5FC9 7d&NRORIGINALURL 2fmethacrylates 2fen 2fproducts 2fmonomers 2flicenses 2fhcntechnolog ... more details
An instant cold pack is a device that consists of two bags, one containing water , which is inside a second bag containing ammonium nitrate . When the inner bag is broken by squeezing the package, the ammonium nitrate is allowed to dissolve in the water in an endothermic reaction. This reaction absorbs heat from the surroundings, quickly lowering the pack s temperature. ref cite web publisher Howstuffworks.com author Marshall Brain title Cold Packs work How Refrigerators Work url http home.howstuffworks.com refrigerator7.htm ref Instant cold packs are a convenient direct replacement for crushed ice used as first aid on sports injury sport injuries . It is also important not to refrigerate before activation. This may result in frostbite if used for prolonged periods of time. For safety reasons, instant cold packs have recently been developed without ammonium nitrate. ref InstaKool An Ammonium Nitrate Free Instant Cold Pack Ammonium Nitrate Free Cold Pack http www.nortechlabs.com instakool instant cold pack.html ref Notes Reflist DEFAULTSORT Instant Cold Pack Category Cooling technology ... more details
An exergonic reaction is a chemical reaction where the change in the Gibbs free energy is negative, ref IUPAC Gold Book definition http www.iupac.org goldbook E02262.pdf search Exergonic 20reaction exergonic exoergic reaction ref indicating a spontaneous reaction . Symbolically, the release of Gibbs free energy, G , in an exergonic reaction is denoted as math Delta G G rm products G rm reactants 0. , math Although exergonic reactions are said to occur spontaneously , this does not imply that the reaction will take place at an observable Reaction rate rate . For instance, the Catalysis Background disproportionation of hydrogen peroxide is very slow in the absence of a suitable catalyst. It has been suggested that eager would be a more intuitive term in this context. ref cite journal doi 10.1021 ed061p710 last Hamori first Eugene coauthors James E. Muldrey year 1984 title Use of the world eager instead of spontaneous for the description of exergonic reactions journal Journal of Chemical Education volume 61 issue 8 pages 710 ref More generally, the terms exergonic and endergonic relate to the Gibbs free energy change in any process, not just chemical reactions. An example of an exergonic reaction is cellular respiration. The terms exothermic and endothermic reactions relate to the enthalpy change of a process. See also Endergonic reaction References reflist Category Thermochemistry de Exergon pl Reakcja egzoenergetyczna ... more details
thermic may refer to one or more of these topics related to heat a past synonym for thermal disambiguation thermal also, thermics was a synonym for thermodynamics the thermic effect of food TEF the thermic reaction of skin , a topic of 19th century hydrotherapy http books.google.com.au books?id nZDveDNq1VwC , but the phrase is also used more recently in other contexts PMID 14876412 thermic reaction may refer to a triggered change in Core temperature body temperature http ajplegacy.physiology.org cgi pdf extract 76 2 284 thermic reaction or thermic process can refer to a chemical reaction that may turn out to be exothermic or endothermic the suffix thermic , as in the following list of thermic inorganic chemistry inorganic reactions involving redox chemical reduction . Highly thermic reactions are those requiring or producing a large amount of heat. Aluminothermic reaction , the thermite reaction being a prominent example Calciothermic reaction Carbothermic reaction Silicothermic reaction thermal lance thermic lance thermic component , thermic composition , thermic effect or thermic reaction may refer to a near explosive property http www.uspto.gov go classification uspc149 defs149.htm thermic reaction or thermic binding can refer to biochemical processes PMID 3542032 disambig ... more details
About biological thermoregulation chemical reactions Endothermic An endotherm is an organism that produces heat through internal means, such as muscle shivering or increasing its metabolism Greek endon within , therm heat . The opposite of endothermy is ectothermy . Mechanisms Generating and conserving heat File Homeothermy poikilothermy.png thumb right Sustained energy output of a warm blooded mammal and a cold blooded reptile animal as a function of core temperature Many endotherms have a larger number of mitochondria per cell biology cell than ectotherms, which enables them to generate heat by increasing the rate at which they metabolize fat s and sugar s. These animals require a much greater quantity of food than ectothermic animals to sustain their higher metabolism. In many endothermic animals, a controlled state of hypothermia , called hibernation or torpor , conserves energy by lowering the body temperature. Many birds and small mammals e.g. tenrec s body temperature drops during daily inactivity, such as at night for diurnality diurnal animals or during the day for nocturnality nocturnal animals, thus reducing the energy cost of maintaining body temperature. Human metabolism also slows down slightly during sleep. The resting human body generates about two thirds of its heat through metabolism inside internal organs in the thorax and abdomen, as well as in the brain. The brain generates about 16 of the total heat produced by the body. ref http users.rcn.com jkimball.ma.ultranet BiologyPages H HeatTransport.html ref Heat loss is a major threat to smaller creatures, as they have a larger ratio of surface area to volume .Small warm blooded animals have thermal insulation ... the rest of the circulatory system. Advantages and disadvantages of an endothermic metabolism The major ... temperature, but often cannot maintain high metabolic activity for as long as endotherms. Endothermic ... and biology. Whereas the thermodynamic terms exothermic and endothermic respectively refer to processes ... more details
number endothermic relate to the enthalpy change in any process, not just chemical reactions. In endergonic ... Endothermic reaction Warm blooded Endotherm References reflist External links Category Thermochemistry ... more details
with I sub 2 sub as the transport agent. Cases of the exothermic and endothermic reactions of the transporting ... requires several days. Alternatively, when the reaction of the solid and the transport agent is endothermic ... 2 sub O H sub rxn sub 0 endothermic The sample of iron III oxide is maintained at 1000 C, and the product ... more details
coke and steam, is strongly endothermic, producing carbon monoxide CO , and hydrogen chem H 2 water gas in older terminology . When the coke bed has cooled to a temperature at which the endothermic ... the temperature of the coke bed followed by the second endothermic reaction, in which the latter ... more details
DISPLAYTITLE Q value nuclear science Other uses Q value disambiguation Q value In nuclear physics and nuclear chemistry chemistry , the Q value for a nuclear reaction reaction is the amount of energy released by that reaction math Q E left text Reactants right E left text Products right , math A reaction with a positive Q value is exothermic has a net release of energy , while a reaction with a negative Q value is endothermic requires a net energy input . ref name Krane cite book author K.S. Krane year 1988 title Introductory Nuclear Physics page 381 publisher John Wiley & Sons isbn 047180553X ref Q values are also featured in particle physics . For example in Sargent s rule , which states that the reaction rate of weak interactions is proportional to Q sup 5 sup . The Q value is the kinetic energy released in the decay of the particle at rest. For example, for neutron decay ref name Martin cite book author B.R. Martin and G. Shaw year 2007 title Particle Physics page 34 publisher John Wiley & Sons isbn 0 471 97285 1 ref math Q m text n m text p m mathrm overline nu m text e c 2 math where m sub n sub is the mass of the neutron , m sub p sub is the mass of the proton , m sub overline &nu sub is the mass of the electron antineutrino and m sub e sub is the mass of the electron . See also Fusion energy gain factor Notes and references reflist External links http www nds.iaea.org queryensdf Nuclear Structure and Decay Data IAEA with query on decays Q values Category Nuclear physics chem stub zh Q ... more details
Orphan date February 2009 unreferenced date June 2009 Direct injection expanded foam molding also known as injection molded foam is a foam manufacturing process that creates soft foam products direct from compound into a final product. This process eliminates the steps required for die cutting and compression molding , as it manufactures the foam and the product simultaneously. The base resin used in a complex formula, is an ethylene based polyolefin elastomer like polyethylene and Ethylene Vinyl Acetate EVA . Foam manufactured with these resins has many physical benefits. Unlike a sponge, foams from this process are closed cell, meaning it s waterproof and resists mold, mildew and bacteria from entering the material. It is also cross linked, which means that the cells are connected in a way that makes the foam strong and durable with high tear and tensile strength. All polyolefin elastomers are also resistant to most chemicals, which allow the products to not only be used in a chemical environment, but also very cleanable with most household cleaners. The process itself is known to be very interesting, because the injected compound is not foam, until an endothermic reaction in a hot mold activates the blowing agents, resulting in an expanded foam part. This requires the mold cavity size to be smaller than the final part. The actual known expansion is created within the formula, so that when the part self ejects from the mold at the end of the cycle, it grows to the required part size. The cavity for a tire is considerably smaller than the final tire size. This process is valuable for any foam product that needs to have lots of detail. It needs to be very durable. External links http www.macho.com upimages tire1.jpg Cavity for a tire DEFAULTSORT Direct Injection Expanded Foam Molding Category Injection molding ... more details
Generalize date September 2011 Image Zinc zinc oxide thermochemical cycle.jpg 350 px right The Zn ZnO cycle The zinc zinc oxide cycle or Zn ZnO cycle is a two step thermochemical cycle based on zinc and zinc oxide ref http www.solarpaces.org Tasks Task2 SHP.HTM Solar Hydrogen Production from a ZnO Zn Thermo chemical Cycle ref for hydrogen production ref http www.hydrogen.energy.gov pdfs review06 pd 10 weimer.pdf Project PD10 ref with a typical efficiency around 40 . ref http www.switt.ch files technologien Solar 20Hydrogen 20Production 04 014.pdf Novel Method for solar hydrogen generation ref Process description The thermochemical two step water splitting process uses redox systems ref http solar.web.psi.ch data research zno roca Solar thermal ZnO decomposition ref Dissociation chemistry Dissociation Zinc oxide ZnO Zinc Zn 1 2 O sub 2 sub Hydrolysis Zinc Zn Water molecule H sub 2 sub O Zinc oxide ZnO Hydrogen H sub 2 sub For the first endothermic step concentrating solar power is used in which zinc oxide is Thermal decomposition thermally dissociated at convert 1900 C F into zinc and oxygen. In the second non solar exothermic step zinc reacts at convert 427 C F with water and produces hydrogen and zinc oxide. The temperature level is realized by using a solar power tower and a set of heliostat s to collect the solar thermal energy . See also Cerium IV oxide cerium III oxide cycle Copper chlorine cycle Hydrosol 2 Hybrid sulfur cycle Iron oxide cycle Sulfur iodine cycle References reflist External links http www.ltnt.ethz.ch people bburg MRS05 Burg.pdf H2 formation by zinc hydrolysis in a hot wall aerosol flow reactor Category Chemical reactions Category Hydrogen production de Solzinc Verfahren nl Zink zinkoxidecyclus ... more details
. Endothermic animals likely evolved from more primitive ectothermic synapsid s sometime in the Permian ... maxilloturbinates, but it shares features with reptiles that suggest it was not fully endothermic. Choana ... , cynodonts continued to diversify, giving rise to fully endothermic mammals in the Late Triassic ... more details
italic title taxobox name Rhizanthes image Rafflesiaceae sp vMH378.jpg image caption Illustration of Rhizanthes then known as Brugmansia , from Der Bau und die Eigenschaften der Pflanzen 1913 . regnum Plant ae unranked divisio Angiosperms unranked classis Eudicots unranked ordo Rosids ordo Malpighiales familia Rafflesiaceae genus Rhizanthes genus authority Dumort. type species Rhizanthes zippelii small Carl Ludwig Blume Blume douard Spach Spach small Rhizanthes is a genus of 4 species of parasite parasitic flowering plants without leaves, stems, roots, or photosynthetic tissue. They grow on roots of a few species of Tetrastigma vines. The genus is limited to the tropical forests of south and south east Asia. The flowers of Rhizanthes vary from 14 to 43 cm in diameter. At least one species of Rhizanthes , R. lowii , is endotherm endothermic . It not only produces it own heat, but has the rare ability to regulate its own temperature. ref name Banzinger cite journal last Banziger first Hans coauthors Bertel Hansen title A new taxonomic revision of a deceptive flower, Rhizanthes Dumortier Rafflesiaceae journal The Natural History Bulletin of the Siam Society year 2000 pages 117 143 url http www.aseanbiodiversity.info Abstract 53001052.pdf ref ref cite journal last Pati o first S. coauthors J. Grace, H. B nziger title Endothermy by flowers of Rhizanthes lowii Rafflesiaceae journal Oecologia year 2000 volume 124 issue 2 pages 149 155 url http www.springerlink.com content fp2hva64w4y2h8xy ref Species Rhizanthes deceptor Sumatra Rhizanthes infanticida S. Thialand, W. Malaysia, Sumatra Rhizanthes lowii Borneo Rhizanthes zippelii W. Java References Reflist External Links http books.google.com books?id F97dSF j0UC&lpg PA58&dq Rhizanthes 20description&pg PA58 v onepage&q Rhizanthes 20description&f false The Flowering of Australia s Rainforests A Plant and Pollination Miscellany br commonscat Malpighiales stub Category Rafflesiaceae ... more details
Refimprove date February 2007 In India there are 410 species ofover 186 genus genera , 45 family biology families and 13 order biology order s out of which nearly 89 species are listed as threatened in the International Union for Conservation of Nature and Natural Resources IUCN Red List of Threatened Animals IUCN 2006 . This includes two species that are locally extinct from India viz. Acinonyx jubatus and Rhinoceros sondaicus . The mammals are the Class biology class of vertebrate animals characterized by the presence of mammary gland s, which in female s produce milk for the nourishment of young the presence of hair or fur specialized tooth teeth the presence of a neocortex region in the brain and endothermic or warm blooded bodies. The brain regulates endothermic and circulatory system , including a four chambered heart . Mammals encompass some 5,500 species including Human s , distributed in about 1,200 genera, 152 families and up to 46 orders, though this varies with the classification scheme. Endangered Mammals Asiatic Golden Cat Felis temmincki Asiatic Lion Panthera leo persica Asiatic Cheetah Acinonyx jubatus venaticus thought to be Extinct now in India Indian Wild Ass or Khur Equus hemionus khur Dhole Asiatic Wild Dog Dhole Cuon alpinus Asiatic Black Bear Selenarctos thibetanus Banteng Bos javanicus Bengal Fox Vulpes bengalensis Eld s Deer Brow antlered Deer Cervus eldi eldi Brown Bear Ursus arctos Jerdon s Palm Civet Paradoxurus jerdoni Amblonyx cinereus Clawless Otter Amblonyx cinereus Clouded Leopard Neofelis nebulosa European Otter Common Otter Lutralutra wild Cat Felis lybica ornata Dugong Seacow Dugong dugon Ganges River Dolphin Platanista gangetica Gaur Bos gaurus Golden Langur Trachypithecus geei Goral Nemorhaedus goral Indian Rhinoceros Rhinoceros unicornis Grey Wolf Indian Wolf Canis lupus Himalayan W toothed Shrew Crocidura attenuate Fact date February 2007 Martes flavigula Himalayan Marten Martes flavigula Himalayan Musk Deer Moschus chrysogast ... more details
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