Steady composition with continuing change
A reversible reaction allows conversion in both directions. When the two rates become equal, macroscopic concentrations can remain constant even though individual entities continue reacting. Equilibrium is therefore dynamic: it requires neither a stopped reaction nor equal quantities of reactants and products in the mixture.
References: [1]
Responding to concentration changes
Adding a reactant or removing a product can disturb the balance and produce a temporary net reaction. The system then approaches equilibrium at a new composition. Qualitative predictions of direction must be supplemented by material balances and equilibrium relationships to determine how much actually changes.
References: [2]
Temperature and gas volume
Temperature can alter equilibrium composition. Compressing a gas mixture has effects that depend on reaction stoichiometry; equal total gaseous amounts on both sides can leave the equilibrium unshifted. Pressure changes consequently do not supply a universal rule favouring products in every reversible chemical reaction.
References: [2]
Balancing conditions in ammonia synthesis
Ammonia synthesis balances equilibrium yield, reaction speed and equipment demands. Catalysts accelerate equilibration, while ammonia separation and gas recycling support continuing production. Equilibrium and kinetic analyses address composition and speed respectively, and industrial process design combines their requirements within the complete operating system.