Effusion-mass spectrometric study of the thermodynamic properties of AlO– and AlO –2

Abstract

Thermodynamic properties were obtained for negative ions of the lower aluminium oxides by means of the effusion-mass spectrometric method over the temperature range 2080 to 2222 K. Second and third law studies were conducted involving negative ions with neutral molecules for the isomolecular reactions AlO(g)+ Cl^–(g)= AlO^–(g)+ Cl(g), AlO₂(g)+ Cl^–(g)= AlO^–₂(g)+ Cl(g). The heats of formation, ΔH_f298, for the ions AlO^–(g) and AlO^–₂(g) obtained from the reaction thermodynamics were –64.6 ± 3 and – 139.3 ± 3 kcal/mol, respectively. The electron affinities were (AlO)= 84.8 ± 3 and (AlO₂)= 94.7 ± 3 kcal/mol.