ISSN:
0538-8066
Keywords:
Chemistry
;
Physical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The bimolecular reaction of HI in CO2, which was excited vibrationally by irradiation of a continuous-wave CO2 laser light, was investigated in the temperature range of 721-980 K. An enhancement of the reaction rate by a factor of about 2.5 was observed in the 1:1 HI—CO2 mixture in comparison with the rate in pure HI when both sample gases were irradiated by a CO2 laser (50 W) at 1 torr. However, in the HI-SF6 mixtures the decomposition rate of HI was not accelerated by irradiation of the CO2 laser. Thus the enhancement is attributed to vibrational excitation of HI through collisional energy transfers from laser-excited CO2 (00°1). At lower total pressures or at lower partial pressures of HI in HI-CO2 mixtures the enhancement was more significant because of inefficient vibrational deactivation of excited HI. A model calculation gave the result in agreement with the experimental one if the effective activation energy is assumed as Ea† = Ea - αEvib, where Ea is the activation energy for the thermal reaction, Evib is the vibrational energy of two colliding HI molecules, and α is estimated to be about 0.7. This means that a part of the vibrational energy of reacting HI is employed to reduce the activation energy for the translational or rotational degree of freedom.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/kin.550131008
