An old building is demolished using TNT (trinitrotoluene), an explosive.

The explosive charges are placed several hours before the demolition. Which equilibria hold just before the charges are detonated?
A. Chemical equilibrium within the TNT
B. Thermal equilibrium between the TNT and its surroundings
C. Mechanical equilibrium between the TNT and its surroundings

A fraction of a second after the charges are detonated, the TNT has reacted to produce hot, high-pressure combustion products. Which equilibria hold at this point?
A. Chemical equilibrium within the reaction products
B. Thermal equilibrium between the reaction products and their surroundings
C. Mechanical equilibrium between the reaction products and their surroundings

A few seconds after the charges are detonated, the reaction products have expanded and reached atmospheric pressure, but remain equite hot. Which equilibria hold at this point?
A. Chemical equilibrium within the reaction products
B. Thermal equilibrium between the reaction products and their surroundings
C. Mechanical equilibrium between the reaction products and their surroundings

Minutes to hours after the charges are detonated, the expanded reaction products have cooled to ambient temperature. Which equilibria hold at this point?
A. Chemical equilibrium within the reaction products
B. Thermal equilibrium between the reaction products and their surroundings
C. Mechanical equilibrium between the reaction products and their surroundings