Accuracy A measure of how close a measured value is to the
Acid acid dissociation constant Ka. Equilibrium constant for the reaction of an
acid, HA, with H2O.
HA + H2O A + H3O+
Ka= A-H+ / HA
Acids (stong/weak) A substance that increases the concentration of H+
when added to water.
Analyte Substance being measured or detected. In the
flask of a titration
Argentimetric A titration using Ag+ ion
Bases A substance that decreases the concentration of
H+ when added to water
Base hydrolysis constant The equilm constant for the reaction of a base, B
B+H2O—BH+ + OH-
Kb=BH+ - OH- / B
Chelate effect The observation that a single multidentate ligand
forms metal complexes taht are more stable than
those formed by several individual ligands with the
same ligand atoms.
Chelating ligand A ligand that binds to a metal through more than
Complexometric titrations A titration in which the reaction between analyte
and tirtant involves complex formation (a
structure consisting of a central atom or ion
(usually metallic), bonded to a surrounding array
of molecules or anions (ligands, complexing
Conj acid base pair An acid and a base taht differ only through the
gain or loss of a single proton
Diprotic acids or bases Compounds that can donate or accept two protons
Endpoint Point in titration at which tere is a sudden change
in a physical property such as indicator colour, pH,
conductivity or absorbance. Used as a measure of
the equivalence point.
Equivelance point Point in a titration at which teh quantity of titrant
is exactly sufficient for stoichiometric reaction with
Formation constant, kf Equilibrium constant for thej reaction of a metal
with its ligands to form a metal-ligand complex.
Conditional formation constant: equilm constant
for formation of a complex under a particular
stated set of conditions, such as pH , ionic
strength, concentration fo auxiliary complexing
species. Fraction of dissociation For teh dissociatio- of an acid (HA), the fraction of
acid in the form A
Fraction of association: for the reaction fo a base
(B) with H2O, the fraction of base in teh form BH+
Hydrolysis Reaction with water. The reaction B+H2O—BH+ +
OH- is the hydrolysis of a base.
Indicators A compound having a physical property (usually
colour) THAT CHANGES ABRUPTLY NEAR THE
EQUIVELANCE POINT of a chemical reaction.
Ligand An atom or a group attached to a central atom in a