Low-Field Mobilities of the Negative Ions in Oxygen, Sulfur Hexafluoride, Sulfur Dioxide, and Hydrogen Chloride

Measurements of the low-field mobility of the negative ions in O₂, SF₆, SO₂, and HCl are described. The results are 2.46, 0.57, 0.35, and 0.71 cm²/v-sec, respectively, reduced to 0^∘{}C and 760 mm Hg pressure. A quantum-mechanical theory of ionic mobility is outlined and applied to the gases investigated experimentally. Comparison of the experimental and theoretical results indicates that the oxygen ion is O₃^-, but attempts to identify the ions in the other gases are inconclusive.