(1) A metal whose potential is highly positive relative to the hydrogen electrode. (2) A metal with marked resistance to chemical reaction, particularly to oxidation and to evolution by inorganic acids. The term as often used is synonymous with precious m ...

An index calculated from total dissolved solids, calcium concentration, total alkalinity, pH and solution temperature that shows the tendency of a water solution to precipitate or dissolve calcium carbonate.

A measure of the acidity or alkalinity of a solution; The negative logarithm of the hydrogen-ion activity; it denotes the degree of acidity or basicity of a solution. At 25

A fracture, usually of' polycrystalline metal, in which most of the grains have failed by cleavage, resulting in bright reflecting facets. It is associated with low-energy brittle fracture.

This potential, sometimes called zeta potential, is a potential difference in the solution caused by residual, unbalanced charge distribution in the adjoining solution, producing a double layer. The electrokinetic potential is different from the electrode ...

The potential of a reversible oxidation-reduction electrode measured with respect to a reference electrode, corrected to the hydrogen electrode, in a given electrolyte.

See mixed potential.

(1) A molecular structure in which a heterocyclic ring can he formed by the unshared electrons of neighboring atoms. (2) A coordination compound in which a heterocyclic ring is formed by a metal bound to two atoms of the associated ligand. See also comple ...

An equation that expresses the exact electromotive force of a cell in terms of the activities of products and reactants of the cell.

See cathodic protection.

The maximum repeated stress that can he endured by a metal without failure under definite conditions of corrosion and fatigue and for a specific number of stress cycles and a specified period of time.

A list of metals and alloys arranged according to their relative corrosion potentials in a given environment. Compare with electromotive series.

A glass membrane electrode used to measure pH or hydrogen-ion activity.

A chemical compound with one or more carboxyl radicals (COOH) in its structure; examples are butyric acid, CH3(CH2)2COOH; maleic acid, HOOCCH-CHCOOH; and benzoic acid, C6H5COOH.

An assembly, consisting of a vessel, electrodes, and an electrolyte, in which electrolysis can be carried out.

Deterioration of metals as a result of the metabolic activity of microorganisms.

Particles of foreign material in a metallic matrix. The particles are usually compounds (such as oxides, sulfides, or silicates), but may be of any substance that is foreign to (and essentially insoluble in) the matrix.

Interfacial reaction equivalent to a transfer of charge between electronic and ionic conductors. See also anodic reaction and cathodic reaction.

A reference electrode composed of mercury, mercurous chloride (calomel), and a saturated aqueous chloride solution.

An electrode immersed in a suitable electrolyte, designed for measurements of electrode potential; A pure metal in contact with a solution of known concentration of its own ion, at a specific temperature develops a potential which is characteristic and re ...