Nuclear reactions endothermic

Also of possible relevance to this dilemma are the findings of Dubrin, McKay, and Wolfgang.125 They studied the reactions of 13N(2Z>) and 1SN( S) produced by nuclear reactions. They found that while both species reacted rapidly with NO, only the more energetic N(2Z>) reacted rapidly with hydrocarbons to give HCN. This is reasonable, since the reaction of ground-state N atoms with, say, C2H4 is either spin disallowed or endothermic. 

A nuclear reaction may involve either the absorption or release of energy hence, the terms endothermal and exothermal are applicable. 

Note, however, that thermonuclear equations refer to individual atoms whereas thermochemical equations generally refer to molar quantities. Just as chemical reactions may be exo- or endothermic, nuclear reactions are sometimes described as exoergic or endoergic... 

There are many nuclear reactions of the type (n, charged particle) used for neutron detection. In general, endothermic reactions are used for fast neutrons, and exothermic ones for thermal neutrons. The endothermic reactions will be discussed in Sec. 14.6. 

Skill 11.4 Analyze bonding and chemical, atomic, and nuclear reactions (including endothermic and exothermic reactions) in natural and man-made systems and apply basic stoichiometric principles. 

The first reaction takes place spontaneously at temperature range of 300-500°C, while the second takes place at temperature range of 750-850°C in the presence of catalyst. Here, the HTGR is uniquely qualified to produce the nuclear heat necessary to drive the intensive endothermic high temperature reactions of H2S04 decomposition to completion. 

The reaction is operated with a negative enthalpy change, generating some entropy loss (5 kj) according to Eq. (9).There is no separation issue. As this reaction is endothermic, heat has to be provided by nuclear heat. Assuming an average pinch of 50 K we find a small exergy loss DH = 3 kj. 

Fignre 8. Diagrams of nuclear configuration for Type 1 reactions, showing the surface touching in the products and its influence in (j). (a) Endothermic cleavages, (b) Exothermic cleavages. From Ref. 76 with permission of Elsevier Sequoia S.A. 

In tire hydrogen production from fossil fiiels, either by the steam-coal gasification reaction or by the steam-nietlrane reforming reaction, the endothermic heat of reaction is conventionally supplied by combustion of fossil fiiels. If this endothermic heat is supplied from nuclear heat, full stoichiometric conversion of fossil fiiels to hydrogen moles and effective conversion of nuclear heat to hydrogen heat can be achieved. 

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