Chemical Equilibrium
A dynamic equilibrium where reactants and products interconvert continuously. At equilibrium, the forward and reverse rates are equal — but it is not static. Disturb it and watch Le Chatelier’s principle restore balance.
Equilibrium State
Le Chatelier’s principle
When a system at equilibrium is disturbed, it shifts to partially counteract the disturbance:
Add reactant A — Equilibrium shifts right, producing more B to consume the excess A.
Increase temperature — For this exothermic reaction, heat favors the reverse reaction. Keq decreases and equilibrium shifts left, producing more A.
Decrease volume — Pressure increases. The system shifts toward fewer gas molecules (toward B, since 2A → B reduces particle count).
The equilibrium constant Keq = [B]/[A]² depends only on temperature. The reaction quotient Q tells you where you are relative to equilibrium: if Q < K, the forward reaction dominates; if Q > K, the reverse dominates.