Dielectric constant, of hydrogen

THE QUANTUM THEORY OF THE DIELECTRIC CONSTANT OF HYDROGEN CHLORIDE AND SIMILAR GASES... 

Lewis made additional valuable contributions to the theory of colored substances, radiation, relativity, the separation of isotopes, heavy water, photochemistry, phosphorescence, and fluorescence. As a major in the U.S. Army Chemical Warfare Service during World War I, he worked on defense systems against poison gases. From 1922 to 1935 he was nominated numerous times for the Nobel Prize in chemistry. Lewis s death, while measuring the dielectric constant of hydrogen cyanide on March 23, 1946, precluded his receiving the prize, which is not awarded posthumously, see also Acid-Base Chemistry Lewis Structures. 

The quantum theory of the dielectric constant of hydrogen chloride and... 

Pauling, L. 1926b. The quantum theory of the dielectric constant of hydrogen chloride and similar gases. Proceedings of the National Academy of Sciences of the United States of America 12 32-35. 

Table III. Bibliography of References The Dielectric Constant of Hydrogen...

The variation of the dielectric constant of the HCl + H2O mixtures is not appreciably different from that of pure water (78.30) at 25°C until the hydrogen chloride concentration teaches a minimum of 0.2%. It increases slightly over the dielectric constant of water as the concentration increases. 

Because of its low dielectric constant, Hquid hydrogen sulfide is a poor solvent for ionic salts, eg, NaCl, but it does dissolve appreciable quantities of anhydrous AlCl, ZnCl2, FeCl, PCl, SiCl, and SO2. Liquid hydrogen sulfide or hydrogen sulfide-containing gases under pressure dissolve sulfur. At equihbrium H2S pressure, the solubihty of sulfur in Hquid H2S at —45, 0, and 40°C is 0.261, 0.566, and 0.920 wt %, respectively (98). The equiHbria among H2S, H2S, and sulfur have been studied (99,100). 

Hydrogen peroxide, when pure, is an almost colourless (very pale blue) liquid, less volatile than water and somewhat more dense and viscous. Its more important physical properties are in Table 14.11 (cf. H2O, p. 623). The compound is miscible with water in all proportions and forms a hydrate H2O2.H2O, mp —52°. Addition of water increases the already high dielectric constant of H2O2 (70.7) to a maximum value of 121 at 35% H2O2, i.e. substantially higher than the value of water itself (78.4 at 25°). 

The rate coefficients obtained with hydrogen iodide show that the effectiveness of halogen acids in catalysing hydrogen exchange is HF > HBr > HI and, as noted above, this was attributed to the difference in dielectric constant of the media. 

It is the hydrogen bond that determines in the main the magnitude and nature of the mutual interactions of water molecules and that is consequently responsible for the striking physical properties of this uniquely important substance. In this section we shall discuss the melting point, boiling point, and dielectric constant of water and related substances other properties of water are treated later (Sec. 12-4). 

It is important to know the influence of the physicochemical parameters of the mobile phase (dipole moment, dielectric constant, and refractive index) on solvent strength and selectivity. The main interactions in planar chromatography between the molecules of the mobile phases and those of solutes are caused by dispersion forces related to the refractive index, dipole-dipole forces related to the dipole moment, induction forces related to a permanent dipole and an induced one, hydrogen bonding, and dielectric interactions related to the dielectric constant. Solvent strength depends mainly on the dipole moment of the mobile phase, whereas the solvent selectivity depends on the dielectric constant of the mobile phase. 

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