TABLE OF CONTENTS Most explosive and propellant compositions contain a mixture of components so as to optimize their performance. Some of the components may not contribute to the heat liberated and may not even contain oxygen. These materials may however, contribute to the gaseous products and reduce the actual temperatures obtained on detonation of the explosive or burning of the propellant. An example of a typical mixed explosive composition is one which contains 60% RDX and 40% TNT, and where the heat of explosion Q has been optimized. In order to calculate the values of Q and V for this composition the oxygen balance and the reaction for decomposition need to be determined. But even before these can be calculated the atomic composition of the mixture must first be established.
Calculations for the atomic composition of 60% RDX/40% TNT are presented in Figure 5.7.
| Explosive substance | Empirical formula | Proportion by mass (g) | Molar mass (g) | Molar proportion in 1g of mixture | Mol of atoms in 1g of explosive mixture | |||
|---|---|---|---|---|---|---|---|---|
| C | H | N | O | |||||
| RDX | C 3H 6N 6O 6 | 0.6 | 222 | | 0.00810 | 0.01620 | 0.01620 | 0.01620 |
| TNT | C 7H 5N 3O 6 | 0.4 | 227 | | 0.01232 | 0.00880 | 0.00528 | 0.01056 |
| Total | 0.02042 | 0.02500 | 0.02148 | 0.02676 |
From the calculations of the atomic composition the empirical formula is found to be C 0.0204H 0.0215
