Irreversible Reaction
A reaction that proceeds essentially to completion, with negligible conversion back to reactants.
Formula / equation
A + B → C
Unit
Dimensionless
In depth
A reaction becomes effectively irreversible when a product escapes the system as a gas, precipitates as an insoluble solid, or is so much more stable that the equilibrium constant is enormous. Strictly all reactions are reversible, but the reverse rate can be immeasurably small.
Examples in the real world
Combustion of methane; the precipitation of AgCl; neutralisation of a strong acid by a strong base.