Biltz table

The parameters y, and K12 are independent of the solvent. Thus, for a molecule moving as a single unit, (Y 2 )/K12 should be a linear function of the molar volume of the liquid solvent at 0°K, V (0). An average value of the solvent molar volume at 0°K was calculated using the methods of Sudgen and Biltz (Table II). A graph of... 

Let us illustrate this simple approach by a few examples, but we first add that numerical values for molar volumes (measured in cm /mol) are converted into the crystallographer s A /f.u. (f.u. = formula unit) by multiplying them by a factor of 1.661 and vice versa. According to the Biltz table, sodium chloride (NaCl) should have a molar volume of 6.5 cm /mol (Na" ") + 20 cm /mol (Cl ) = 26.5 cm /mol. In a given crystal structure, a single formula unit of NaCl will therefore occupy 44.0 A. In fact, the crystal structure of NaCl has a lattice parameter of 5.64 A and a unit cell volume of 179.4 A with four formula units, which yields an experimental 44.9 A per formula unit and an incremental error of only 2%. ... 

Values quoted are from "International Critical Tables or from W. Biltz, Z. anorg. Chem., 170, 161 (1928), and D. M. Bose, Z. Physik, 65, 677 (1930). I am indebted to Mr. P. D. Brass for collecting from the literature some of the data in this table. 

Using that classification, Redkin modified Biltz and Klemm s table (see Table 3). That classification was confirmed by Nakamura and Itoh [52], who found that the specific conductivity of molten alkali chlorides increases monoton-ically with decreasing cation radius, as shown in Figure 6. In the case of chlorides of alkaline earth metals there is a break at CaCl2, and the specific conductivity decreases dramatically when going to Mg2+ and Be2+. This break may be attributed to complex formation among the component ions in those molten salts [53], This means that in the molten alkali halides there are free ions and no complex formation, a fact confirmed by Raman spectroscopy [52],... 

FIGURE 17 Periodic Table of Biltz (1902) with an intraperiodic accommodation of the rare earths. Reproduced from Biltz (1902). 

W. Klemm and W. Biltz, The Distribution of Ionic Conductivity among Molten Chlorides of the Periodic Table, Z. Anorg. Allg. Chem. 152 255, 267 (1926). 

A direct measurement of the enthalpy of formation has not been made. An estimate of A H is obtained by a method suggested by Parker (p and used in the BeBrgCcr) table (2). Biltz and Messerknecht (3) have measured the enthalpies of... 

Historically, Retgers (7) in 1895 classified all the lanthanides in one group and this was later followed up by Steele, Biltz and Brauner (2-4). It was Brauner (4), who first attempted to subdivide the lanthanides into several subgroups on the basis of the hydrolyzing activity of their salts including the higher oxides of Ce and Pr (Table 1). 

Table 19.1 Storage properties for the ammines of 30 metal halides. For each salt the tabulated values are the hydrogen density of the stable ammine at 0°C and 1 bar ammonia, the vapour pressure of this ammine at 100°C, the temperature where the highest and lowest coordinated ammines reach an equilibrium vapour pressure of 1 bar, and the enthalpies for release of ammonia from the stable coordination compounds. All data are calculated from Biltz (1923) and Lepinasse and Spinner (1994)... 

Table 4. Volume of the unit cell Ve,Z = 4 volume per formula unit Vf, as well as the observed volume differences (Vo) and the calculated volume differences according to Biltz (Vo).

It transpires that the above goal has already been accomplished, partly so, in the early 20th century due to the work of Biltz and coworkers [33]. Based on the available experimental data of pyknometric and X-ray-based densities of inorganic (and also organic ) solid-state materials at that time, a tabulation referring to absolute zero temperature and a standard pressure of 1 atm was proposed it is given in Table 1.2. 

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