Selenium magnetic susceptibility

Table V-2 Re-evaluated second and third law enthalpy of formation of Se2(g) at 298.15 K as obtained from mass spectrometric investigations and determinations of the magnetic susceptibility of selenium gas. The last column contains the values evaluated by Gronvold, Drowart, and Westrum [84GRO/DRO] from the cited references. The value attributed to [84GRO/DRO] in the first column was evaluated from the measurements of Tobisawa [60TOB] who did not originally evaluate partial pressures or thermodynamic properties.

Tobisawa, S., Magnetic susceptibilities of sulfur, selenium and tellurium from room temperature to 1100 C, Bull. Chem. Soc. Jpn., 33, (I960), 889-893. Cited on page 97. 

Magnetic susceptibility (I8°) —0.31 x 10-( cgs. Hardness (Mohs) 2,3. Modulus of elasticity 6,000,000 psi. Specific heat (solid) 0.047 cal/g/"C. Thermal conductivity 0.014 at 20°, Burns in air with a greenish -blue flame, forming the dioxide. Insol in water, in benzene, in carbon disulfide. Not attacked by hydrochloric acid reacts with nitric acid with coned or fuming sulfuric acids, forming a red soln in presence of air dissolves in potassium hydroxide with formation of a deep-red sola. Combines with the halogens does not react with sulfur or selenium. 

Information concerning reaction rates can be of interest in explaining the observed time needed to attain equilibrium in the T range between the mp and Tp. The results of the magnetic susceptibility and the ESR measurements are compared to theory in Figs. 1 and 2 in 15.2.2.2.5 for sulfur and selenium, respectively. 

Fig. 5.10. Temperature dependence of the magnetic susceptibility of liquid selenium along the liquid-vapor coexistence curve. Squares denote experimental values from Gardner and Cutler (1979) triangles denote data from Freyland and Cutler (1980).

Fig. 5.12. Average degree of polymerization (atoms per chain) as a function of temperature for liquid selenium (Warren and Dupree, 1980). Full curves, Nchain from resonance shift analysis tmd Eq. (5.7) assuming /. = 0 dashed curve, Nc am from magnetic susceptibility broken curve (ET), calculated from theory of ring-chain equilibrium by Eisenberg and Tobolsky (1960).

Fig. 7.3. Internally pressured cell for magnetic susceptibility measurements of fluid selenium by the Faraday method (Freyland and Cutler, 1980). The sealed quartz capsule containing the sample is mechanically supported by the surrounding molybdenum pressure cell.

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