Kistiakowsky-Wilson decomposition reactions

The reaction for the decomposition of explosive substances can therefore be determined using either the Kistiakowsky-Wilson (K-W) rules... 

Table 5.7 Reactions for decomposition products using the Kistiakowsky-Wilson...

The thermochemistry of explosive compositions has been discussed in detail in Chapter 5. The Kistiakowsky-Wilson and the Springall Roberts rules both give an approximate estimate for the products of decomposition, which is independent of the temperature of explosion. The formulae and calculations for determining the heat of explosion also assume that the explosive reactions go to total completion. However, in practice the reactions do not go to completion and an equilibrium is set up between the reactants and the products. This equilibrium is also dependent upon the temperature of the explosion Te. 

In order to determine the products of decomposition for equilibrium reactions the Kistiakowsky-Wilson or the Springall Roberts rules can be applied as a starting point. From the products of decomposition the heat and temperature of explosion can then be calculated. The temperature of explosion can then be used to calculate the products of decomposition. In practice, this process is repeated many times until there is agreement between the answers obtained. Equilibria of complex reactions and of multi-component systems are today obtained by computer however, the ability to use tabulated data is useful in predicting the direction and extent of the reaction. 

As a starting point the decomposition products for RDX (C3H6N6Oe) are calculated from the Kistiakowsky-Wilson rules (Q = —21.60) as shown in Reaction 6.2. 

The reaction for the decomposition of explosive substances can therefore be determined using either the Kistiakowsky-Wilson (K-W) rules or the modified Kistiakowsky-Wilson (mod. K-W) rules. Tables 5.7 and 5.8 present equations for the decomposition for some explosive materials using the Kistiakowsky-Wilson and the modified Kistiakowsky-Wilson rules, respectively. 

The reaction for the decomposition products of the mixed explosive composition can be determined by applying the modihed Kistiakowsky-Wilson rules as shown in Table 5.16. 

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