Note that the strict separation of nuclear and electronic motion (the Born - Oppenheimer approximation) which is a tenant of the Ball & Springs description of molecular structure becomes vague in this instance

Hydroxide ion, OH^-_(aq), also has a similar mechanism of migration in water:

In the above examples of ion mobility (attributed to Grotthus, circa 1600??) the connectivity of the hydrogen bonding network has been greatly simplified. A likely conformation ( at least transiently stable) for H⁺ in water might look like

Unlike most equilibrium constants, The acid equilibrium constant is taken as a property of a molecule not a chemical reaction. This is because the acidic properties of a species described by this number are associated with the assumed aqueous acid base reaction:

This definition effectively compares all aqueous acids to Hydronium ion, which clearly has a K_a of unity. All acids with K_a's of greater than one are defined as strong acids.

Here are some of stong acids: HCl, H₂SO₄ (first ionization), HNO₃, HI, HBr, HClO₄

Similarly, Base strength is compared to that of aqueous Hydroxide ion:

Strong bases, those with K_b's greater than one, are: NaOH, S^-2, O^-2

The conjugate base of any given acid may be characterized as to its base strength, but this is not independent of acid strength. The K_b of an arbitrary conjugate base is defined as the equilibrium constant of the following equation

The sum of this reaction and the reaction of the acid with water is

Thus, it is clear that for conjugate acid base pairs:

The dissociation of weak acids and bases may be solved in the same way as any other equilibrium problem. Consider the dissolution of n_HA⁰ moles of a weak acid in volume V of pure water.

Where [H₃O⁺]_e = [A^-]_e = x_e/V and [HA]_e = (n_HA⁰ - x_e)/V