The dissociation constant of an electrolyte such as a weak acid HA is a measure for the degree of dissociation of HA into H+ and A-. The dissociation constant is expressed as the product of the concentrations of the dissociated species divided by the concentration of the undissociated species : KHA = [H+] x [A-] / [HA] For more information click here
For systems in which ligands of a particular kind bind to a receptor in a solvent there will be a characteristic frequency with which existing ligand-receptor complexes dissociate as a result of thermal excitation, and a characteristic frequency with which empty receptors bind ligands as a result of Brownian encounters, forming new complexes. The frequency of binding is proportional to the concentration of the ligand in solution. The dissociation constant is the magnitude of the ligand concentration at which the probability that the receptor will be found occupied is 1/2.
number indicating the extent to which a molecule dissociates in solution to form free ions. For a simple two-component system (e.g.: CH3COOH CH3COO- + H+) it is the product of the molar concentration of the two ions divided by the molar concentration of the undissociated molecule: K = ([CH3COO-] x [H+]) / [CH3COOH]. The smaller the value of K, the less dissociation is present. K varies with temperature, ionic strength, and the nature of the solvent.
the equilibrium constant for a reversible dissociation
A number that represents the essentially steady equilibrium constant for a weak solution. Also known as ionization constant.
Dissociation constant is a constant whose numerical value depends on the equilibrium between the undissociated and dissociated forms of a molecule. A higher value indicates greater dissociation. The term dissociation is also applied to ionisation reactions of acids and bases in water. For example HCN + H2O H2O+ + CN- which is often regarded as a straightforward dissociation into ions HCN H+ + CN- The equilibrium constant of such a dissociation is called the acid dissociation constant or acidity constant, given by The concentration of water [H2O] can be taken as constant. Similarly, for a base, the equilibrium NH3 NH4+ + OH- is also a dissociation; with the base dissociation constant or basicity constant, given by b) is a measure of the strength of the acid (base).
A value which quantitatively expresses the extent to which a substance dissociates in solution. The smaller the value of K, the less dissociation of the species in solution. This value varies with temperature, ionic strength, and the nature of the solvent.
Equilibrium constant that applies to the dissociation of a comples ion into a simple ion and coordinating species (ligands).
the measure of the extent of dissociation, measured by the dissociation constant . For the process: AB = A + B = ([A][B])/[AB
the inverse of the formation constant, which is the equilibrium constant for the reaction in which ligands replace water molecules in binding to a complex ion. So if the dissociation constant is high, the formation constant is low and fewer ligands are binding with metal ions.
See equilibrium constant.