Ion neutralization reactions in irradiated hydrogen chloride, hydrogen bromide, and nitrous oxide

Abstract

Rates of ion neutralization have been measured in hydrogen chloride, hydrogen bromide, and nitrous oxide by collecting the ions remaining in a defined v o l~~n~e at various times after ionization by a pulse of 120 k.v.p. X-rays. Values of the total homogeneous ion-ion recombination coefficient, rl, have been obtained for each gas over a range of pressures in the region 50 to 650 Torr. From a study of the effects of pressure and ion density, the relative rates of wall diffusion, mutual neutralization, and three-body neutralization have been deduced.

Hydrogen forming reactions of thermal electrons in hydrogen halides: kinetics and thermodynamics

“…Since XHX-ions are probably the main longlived negative ion species in the absence of SF6 (see below), the use of this scavenger should have the advantage of not affecting ion recombination reactions. This conclusion is supported by the fact that the recombination coefficient in HC1 is unafl'ected by SF6 (55). It may be noted that rates of HX capture calculated from previous results with CC14 and C7FI4 (4, 6) are within a factor of two of those for SF6.…”

Radiation chemistry of ethanol :

“…However, the collision efficiencies of 3 and 5 might be less than unity. Assumed to be equal to the rate constant in other molecular gases at pressures in the vicinity of 1 atm (679028,679027,679029,670319,700046).…”

An Ionization Chamber Study of Electron and Ion Decay in Irradiated Ammonia

“…Ion-ion neutralization reactions in gases at normal pressure typically have neutralization coefficients of 3 x ion cm-3 s-' or less (5,15) and the present value of a is some ten to twenty times larger. In a preliminary note (13) this was attributed to the approximately hundredfold larger relative velocity for electron-ion collisions, and it should be noted that the three other neutralization reactions reported to have a 2 cm3 ion-' s-' involve collisions of this type.…”

“…In this connection it should be noted that the positive NH,' ions would have been heavily clustered in ammonia at the temperatures and pressures used here. Indeed from the results of high pressure mass spectrometry (9) we conclude that the proportion of ions with n less than 5 taking part in reaction 5 [5] e + NH,+.IINH~ + Neutral products would have been negligible. Furthermore, n may be as large as twenty, and ionic radii of 8 A and higher may be expected.…”

“…The X-ray unit and rotating sector have already teen described (5). The pulse widths used here were 17.6 or 30 ms, each being followed by an identical decay period.…”