Explosions

Question 1

Types of explosions

Answer 1

Thermal explosion = exo overall reaction, drive increase in local temp, increase in rates of initiation/propagation steps with significant Ea
Chain branching explosion = no of chain carriers increases exponentially, increases rates of propagation/branching steps = more chain carriers

Question 2

Chain branching explosion limits

Answer 2

Low pressure = chain carriers lost at walls = steady reaction
P > 1st explosion limit = branching/propagation steps take over = chain branching explosion
P increases sufficiently = gas-phase termination so chain carriers lost at walls = steady reaction
P increases sufficiently at a given temp = enough energy per given volume = thermal explosion