A Mass-Spectrographic Analysis of the Ions Produced in HCl Under Electron Impact

Abstract

An investigation has been made by a mass spectrograph of the ions formed in HCl under electron impact. The following ions were observed: H${\mathrm{Cl}}^{+}$, H${\mathrm{Cl}}^{2+}$, ${\mathrm{H}}^{+}$, ${\mathrm{Cl}}^{+}$, ${\mathrm{Cl}}^{2+}$, ${\mathrm{Cl}}^{3+}$, ${\mathrm{Cl}}^{4+}$, ${\mathrm{Cl}}^{5+}$, and ${\mathrm{Cl}}^{-}$. When He and Ne were used as calibrating gases, the following appearance potentials were determined: H${\mathrm{Cl}}^{+}$, 12.9±0.2 volts; H${\mathrm{Cl}}^{2+}$, 35.7±1.0; ${\mathrm{H}}^{+}$, 18.6±0.3 and 28.4±0.3; ${\mathrm{Cl}}^{+}$, 17.2±0.5 and 21.2±0.5; ${\mathrm{Cl}}^{2+}$, 45.7±0.3; ${\mathrm{Cl}}^{3+}$, approximately 160; ${\mathrm{Cl}}^{-}$, approximately 1.6 volts. The efficiency of ionization curves were of the usual form. From the ratio of the peak heights of H${\mathrm{Cl}}^{35}$ to H${\mathrm{Cl}}^{37}$ the abundance ratio ${\mathrm{Cl}}^{35}$/${\mathrm{Cl}}^{37}$ was found to be 3.07±0.03. ${\mathrm{Cl}}^{39}$ if present was less than 1/20,000 of ${\mathrm{Cl}}^{35}$.