Heats of combustion, explosion and formation

Values for heats of combustion, explosion and formation for some expls of military interest are given in Tables A B compiled from various sources (See opD380 D381) Refs 1) M. Berthelot C. Matignon, CR 113, 246(1891) (Chaleur de combustion)... 

Heats of Combustion, Explosion and Formation For Some Explosives of Militory Interest ... 

Heats of combustion of explosives deficient in oxygen (See Vol 1 of Encycl, p A515, under "Available Oxygen ) are always higher than either their heats of explosion or of detonation. For expls with positive oxygen balance to CO2, like NG, there should not be any difference between these values Values for heats of combustion may be found in the same sources as indicated under "Heat of Formation . Some selected values for explosives are given in the Table which is at the end of "Heat of Explosion and Heat of Detonation ... 

Parks, JACS 61, 3543(1939) (Heats of combstn 17) R.R. Wenner, "Thermoche-mical Calculations , McGraw-Hill, NY(1941), pp41-6, 48-9, 51-6, 74 109-11 (Heats of formation) 42, 43 46-9 (Heats of combustion) (No heats of explosion or detonation are given) 18) G.B. Kistiakowsky, OSRD Rept 293 1941) (Determination of heats of combustion of expls) 19) E.J. Prosen F.D. Rossini, JResNatIBurStandards 27, 289(1941) (Calorimetric bombs of Prosen Rossini) 20) G.B. Kistiakowsky, OSRD Rept 702(1942) (Heats of combstn and of... 

Heat of Combustion. See Vol 4, p D369 (Tables D380-1) of Encycl under DETONATION (AND EXPLOSION), DEFLAGRATION (AND COMBUSTION), AND FORMATION, HEATS OF... 

The net heat difference between the heats of formation of the reactants and products in a chemical reaction is termed the heat of reaction . For oxidation, this heat of reaction may be termed heat of combustion . The energy liberated when explosives deflagrate is called the heat of deflagration whereas the energy liberated on detonation of explosives is called the heat of detonation in kj mol"1 or the heat of explosion in kj kg"1. In primary explosives, which are used as initiators,... 

The specific heat of cyclonite is 0.30 cal/g°C, its heat of combustion 2285 kcal/kg, and its heat of formation — 96 kcal/kg, i.e. — dHf=—21.3 kcal/mole. Cyclonite is therefore an endothermic compound and this is one of the factors which render it so highly explosive. 

Heat of Combustion — 16l6cal/g Heal of Detonation — 1486cal/g Heat of Explosion — I600cal/g Heat of Formation — 400cal/g Heat Test at 100° — % loss in first 48 hrs 3-6, in 2nd 48 hrs 3-5 and no expln in 100 hrs... 

Its expl and other props, given in R.efs 2,3,4 5), are as follows Ballistic Mortar Value (Power) 127%TNT Explosion Temperature ignites ca 340°, but does not expl even at 360° (same as for TNT) Friction Sensitivity- si less sensitive than RDX Heat of Combustion, Qc 769.8 kcal/mole Heat of Explosion, Qe 272.6 kcal/mole Heat of Formation, 27.8 kcal/mol Hygroscopicity- increase in wt at 100% RH 0.09% vs 0.03% for TNT not hygroscopic at 90% RH Impact Sensitivity, detd by BurMinesApp No 5- si less sensitive than PETN 75° International Heat Test loss of wt in 48 hrs 0.1% vs 0.2% for TNT Power- see Ballistic Mortar Value and Trauzl Value Stability. Thermal at 100°- no expln in 300+ mins(same as for TNT) Stability, Thermal at 2 35°- methyl violet turned salmon pink in 30 mins vs 300+ mins for TNT Temperature of Explosion 3885°K Trauzl Test Value 135% TNT ... 

Heat of Combustion (Qc), Heat of Explosion (Qe) and Heat af Formation (Qf) will be discussed under Calorimetric Tests in Vol 11. 

An important point to remember is that the heat of formation of an explosive is only one of the terms in the determination of heat of detonation or heat of combustion. It is also one of the smaller terms, as compared to the values of the typical products such as water and carbon dioxide. A large error in the estimation of the A// of the explosive, say around 25 or 30 (kcal)/(g mole), would only introduce a relatively small error in the estimation of A/Zj. Most explosives have a A//3 in the neighborhood of 300 (kcal)/(g mole), and so the 30 (kcal) error in A// only represents an error of 10% in A//S-... 

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