INDEX endothermic

CYANO COMPOUNDS, DIENES, HALOACETYLENE DERIVATIVES, HALOGEN OXIDES, METAL ACETYLIDES, METAL FULMINATES, OXIDES OF NITROGEN The individually indexed endothermic compounds, for most of which heats of formation are given in the text f Acetonitrile, 0758... 

Several members of this (often endothermic) group of compounds which contain heavy metals tend to explosive instability, and most are capable of violent oxidation under appropriate circumstances. Fusion of mixtures of metal cyanides with metal chlorates, perchlorates, nitrates or nitrites causes a violent explosion [1], Addition of one solid component (even as a residue in small amount) to another molten component is also highly dangerous [2], Individually indexed compounds are ... 

The oxides of nitrogen collectively are oxidants with power increasing with oxygen content. Dinitrogen oxide will often support violent combustion, since its oxygen content (36.5%) approaches double that of atmospheric air. Nitrogen oxide and dinitrogen oxide are both endothermic and capable of detonation in the liquid state. Individually indexed oxides are ... 

Metal cyanides are readily oxidised and those of some heavy metals show thermal instability. The covalent cyano group is endothermic, and hydrogen cyanide and many organic nitriles are unusually reactive under appropriate circumstances, and A -cyano derivatives are reactive or unstable. The class includes the groups and individually indexed compounds are f Acetonitrile, 0755 f Acrylonitrile, 1104... 

Of the various compounds arising from union of oxygen with one or more halogens, many are endothermic and all are generally unstable but powerful oxidants. Individually indexed compounds are ... 

The conversions in a PMMR for an endothermic and an exothermic reaction as a function of the reactor temperature are given in Figure 11.24 and Figure 11.25, respectively. The intersection of a material balance curve with a given ratio of the permeation to reaction rate and an energy balance line with a known heat generation index provides the conversion under the operating conditions. 

A crystalline phase of beryllosilicate with analcime structure was obtained under hydrothermal conditions from starting material of composition NasBe15Si50ls NaCl. An analcime-like phase was obtained as a nearly pure phase at 200°C. A small amount of sodium chloride coexisted with the above phase. The lattice constant was a = 13.35 it 0.01A. The refractive index was 1.519 it 0.002, higher than that of normal analcime. The broad endothermic peak, indicating the dehydration of zeolitic water, was observed in the temperature range from 150° to 500°C on a DTA curve. The specimen showed little change of structure on heating to 500°C. These results indicate that a beryllosilicate with the analcime structure was prepared by direct synthesis. 

Qualitatively we may use jS as an index of the transition state along the reaction path. If the transition state is reactant-like m 0 (Fig. 3) and 13 is thus close to zero when the transition state is product-like Wj = 0 (Fig. 3) and j8 is thus unity. The usually linear Bronsted relationships occurring in nature presumably result from a relatively small change in equilibrium constant as the reaction changes from endothermic to exothermic there should be a smooth change from y8 = 1 to P = 0. 

Sample Test Data. Thirty different NLO chromophores were tested to provide a thermal stability index. Of these, seven were studied using both melting endotherm and decomposition exotherm disappearance whereas the other twenty-three compounds were studi using only the decomposition exotherm decreases. makes a total of thirty-seven samples whose data are given in Table m. The chemical structures corresponding to the sample names are shown in Figures 5,6 and 7. 

The Dow Fire and Explosion Index (FEI) (Dow, 1994 Van den Braken, 2002) and the Dow Chemical Exposure Index (CEI) have been developed and practiced hy Dow Chemicals for several decades. These tools measure process inherent safety characteristics, help to quantify the expected damage of potential fire and explosion incidents, and identify equipment that would likely contribute to the creation of the incident. The Mond Index was developed by ICI (UK) from the Dow Fire and Explosion Index. The Mond Index includes toxicity and covers a wider range of processes and storage installations than the FEI. The various aspects considered in the FEI are material factor (flammability and reactivity), general process hazards such as exothermic/endothermic reactions, and special process hazards such as toxic nature of the chemicals and dust explosion. For example. Table 8.6 shows the results of the FEI for various inventory levels of storage of ethyl acrylate. 

To take account of the enthalpy absorbed by endothermic breakdown of the filler and raising the temperature of its decomposition products, an extra term directly proportional to the loading must be subtracted from the right hand side of this equation. Assuming that all the terms in Equation 6.1 are not significantly affected by filler incorporation, the reciprocal of the oxygen index can be directly related to filler loading / as shown in Equation 6.2 ... 

As seen previously, the endotherm and heat adsorbing effects can contribute markedly to the heat balance in the conventional oxygen index test, where only a small fraction of the heat of combustion is fed back. In other tests such as UL94 and particularly radiant heat tests, these effects probably become less significant and other factors... 

We have shown a relationship between impact and shock sensitivity and illustrated how a sensitivity index based on oxygen balance can be used to estimate sensitivity in closely related series of molecules. It is shown that the critical temperature of an explosive calculated by the Frank-Kamenetskii equation correlates fairly well with the shock sensitivity of the material. This supports the idea that the shock or impact initiation of an explosive is primarily a thermal event and not dominated by pressure driven chemistry. The concept of the "trigger linkage" in explosives is discussed and it is pointed out that insensitive explosives will require early chemistry that is thermochemically neutral or endothermic and leads to the build-up of later strongly exothermic chemistry. 

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