| 释义 |
Ostwald|ˈɒstwəld|
The name of Wilhelm Ostwald (1853–1932), Russian chemist, used attrib. and in the possessive to denote apparatus invented and principles enunciated by him, as Ostwald('s) dilution law, the law that for dilute solutions of a binary electrolyte the square of the degree of dissociation of the solute, multiplied by its concentration, and divided by one minus the degree of dissociation, is a constant for the solute; Ostwald pycnometer, a pycnometer in the form of a bulb joined at the top to a horizontal capillary tube and at the bottom to a U-tube bearing a graduation at the level of the capillary; Ostwald('s) viscometer, an instrument in which the viscosity of a liquid is determined by the time taken for a measured volume to pass through a capillary bore in a U-tube.
[1899J. Walker Introd. Physical Chem. xxi. 227 Certain empirical relations have..been found connecting the degree of dissociation and the dilution, and these have a form similar to that of Ostwald's dilution formula.] 1902H. C. Jones Elem. Physical Chem. vii. 354 (heading) Testing the Ostwald dilution law. 1930C. W. Davies Conductivity of Solutions i. 12 Ostwald's dilution law breaks down completely when it is applied to solutions of the common salts. 1973A. W. Adamson Textbk. Physical Chem. xii. 538 Weak electrolytes obey the Ostwald dilution law well, and their behavior is thus determined primarily by a dissociation equilibrium.
1910A. Ewell Text-bk. Physical Chem. 25 An Ostwald pyknometer is very convenient as a weighing pipette. 1962Perry & Koenig in A. Pirie Lens Metabolism Rel. Cataract 306 For viscosity measurements, Ostwald viscometers were used to measure flow rates at 25°C. Densities were measured with Ostwald pycnometers.
1924Abstr. Bacteriol. VIII. 2 Direct inoculation of the sterilized gelatin culture media in Ostwald's viscometer was tried for a period of 3 months. 1967Margerison & East Introd. Polymer Chem. ii. 103 The usual method employed to measure the solution and solvent viscosities utilizes an Ostwald viscometer. |