An entropic explosion is an

explosion An explosion is a rapid expansion in volume of a given amount of matter associated with an extreme outward release of energy, usually with the generation of high temperatures and release of high-pressure gases. Explosions may also be generated ...

in which the reactants undergo a large change in volume without releasing a large amount of

heat In thermodynamics, heat is energy in transfer between a thermodynamic system and its surroundings by such mechanisms as thermal conduction, electromagnetic radiation, and friction, which are microscopic in nature, involving sub-atomic, ato ...

. The

chemical decomposition Chemical decomposition, or chemical breakdown, is the process or effect of simplifying a single molecular entity, chemical entity (normal molecule, reaction intermediate, etc.) into two or more fragments. Chemical decomposition is usually regarded ...

of triacetone triperoxide (TATP) may be an example of an entropic explosion. It is not a thermochemically highly favored event because little energy is generated in

chemical bond A chemical bond is the association of atoms or ions to form molecules, crystals, and other structures. The bond may result from the electrostatic force between oppositely charged ions as in ionic bonds or through the sharing of electrons a ...

formation in reaction products, but rather involves an

entropy Entropy is a scientific concept, most commonly associated with states of disorder, randomness, or uncertainty. The term and the concept are used in diverse fields, from classical thermodynamics, where it was first recognized, to the micros ...

burst, which is the result of formation of one

ozone Ozone () (or trioxygen) is an Inorganic compound, inorganic molecule with the chemical formula . It is a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope , break ...

and three

acetone Acetone (2-propanone or dimethyl ketone) is an organic compound with the chemical formula, formula . It is the simplest and smallest ketone (). It is a colorless, highly Volatile organic compound, volatile, and flammable liquid with a charact ...

gas phase molecules from every molecule of TATP in the solid state. This hypothesis has been questioned as opposing to other theoretical investigations as well as actual measurements of the detonation heat of TATP. Experiments have shown that the explosion heat of TATP is about 2800 kJ/kg (about 70% of TNT) and that it acts as a usual explosive, producing a mix of hydrocarbons, water and carbon oxides upon detonation. The authors of the 2005 Dubnikova et al. study confirm that a final redox reaction (combustion) of ozone, oxygen and reactive species into water, various oxides and hydrocarbons takes place within about 180 ps after the initial reaction - within about a micron of the detonation wave. Crystals of TATP ultimately reach a temperature of 2300 K and pressure of 80 kbar.

References

Chemical reactions Thermodynamic entropy Explosions {{explosive-stub