Mass spectrometric determination of the dissociation energies of the molecules GeS, ScS, YS, LaS and CeS

Abstract

The dissociation energies of the gaseous monosulphides GeS, ScS, YS, LaS and CeS were determined: Dz(GeS) = 130.9f0.6; D;(ScS) = 113-4f2.5; DG(YS) = 125-7&2-5; D8(LaS) = 1373 Ifi2-5 and Di(CeS) = 136.0f3.0 kcal/mole. In an appendix, selected values for the dissociation energies of the monoxides ScO, Lao, YO, CeO and VO are given : DZ(Sc0) = 160.4f2.0 ; DZ(Y0) =170.4f2.5; Dz(La0) = 190.3f2.5; Dg(Ce0) = 188-6f3-5 and Dg(V0) = 148.8f2-5 kcal/ mole.

Thermodynamic study of gaseous vanadium phosphates by high‐temperature mass spectrometry

“…We adopted Δ f H 0 (298.15) = 133.3 AE 10.0 kJ/mol for VO (g) and À182.7 AE 15.0 kJ/mol for VO 2 (g). These values are averaged results from Berkowitz et al, [24] Coopens et al [25] and Killingbeck [26] obtained according to the second law, results from Farber et al [27] obtained according to the third law, and from Frantseva and Semenov, [28] Banchorndhevakul et al [29] and Balducci et al [30] obtained according to the third law. These values show good agreement.…”

Thermochemistry of (germanium + sulfur) IV. Critical evaluation of the thermodynamic properties of solid and gaseous germanium(II) sulfide GeS and germanium(IV) disulfide GeS2, and digermanium disulfide Ge2S2(g). Enthalpies of dissociation of bonds in GeS(g), GeS2(g), and Ge2S2(g)

“…Gurvich et al discussed only the spectroscopic result in connection with D°m(GeS) and made no mention of other measurements, notably by Drowart and his colleagues, who used combined mass-spectrometric, Knudsen effusion, (48) and photoionization (49) techniques. In the first of those, the equilibrium constant K for the reaction:…”

“…They then adjusted that result to refer to the ground states of the product atoms: Ge( 3 P 0 ) and S( 3 P 2 ), and thus selected D°m(GeS)=(547.5320. 48 …”

Inorganic Compounds

“…b Average value from Semenov (1965), Smoes et al (1965), Ames et al (1967), Coppens et al (1967) and Drowart et al (1967). The dissociation energy for ScB, however, is significantly larger than that for Sc 2 .…”