Equilibrium

Definition

Equilibrium here means the forward and reverse reactions occur at equal rates, not that the system is still or silent. It is equal traffic in both directions.

In water, hydronium and hydroxide are constantly formed by self-ionization and recombine almost immediately, holding their populations steady. pH reports where a linked equilibrium currently sits, describing the present intensity rather than a fixed amount. Acids and bases force the equilibrium to a new resting point but never suspend it.

Related concepts

Self-ionization of water · pH as equilibrium position · Acid base equilibrium tug-of-war

---

Part of The Blueprint of Water · 🧪 chemistry