Mechanism of Hydrogen Formation by Electrons in x- or γ-Irradiated Gaseous HCl

Journal of Chemical Physics - Tập 48 Số 3 - Trang 1235-1241 - 1968
R. S. Davidow1, David A. Armstrong1
1Chemistry Department, The University of Calgary, Calgary, Alberta, Canada

Tóm tắt

Studies of the effects of Cl2 and SF6 on the production of hydrogen from the x or γ radiolysis of gaseous HCl indicate that 2.5 ± 0.1 electrons per 100 eV form an intermediate Hα, which is not a thermal hydrogen atom. The remainder of the total yield of 4.0 electrons per 100 eV give rise to thermal hydrogen atoms. The results can be explained satisfactorily on the basis of the electron-capture reactions (6a) and (6c) (see text), where the sum of k6a and k6c lies in the range 5 × 10−32 to 2.6 × 10−30 ml2 molecule−2·sec−1. Hα is taken to be a clustered form of HCl− which either produces molecular hydrogen in further reactions with HCl molecules, or is scavenged by Cl2. The rate constant ratio kHα+HCl / kHα+Cl2 was 8 × 10−6 at − 77° ± 2°C and 1.2 ± 0.3 × 10−3 at 1° ± 1°C. Chlorine competes with HCl for the thermal hydrogen atoms formed in Reaction (6a) as well as for Hα, and at − 77° ± 2°C kH+HCl / kH+Cl2 was found to have a value of 2.6 ± 0.7 × 10−3, in good agreement with the data of Klein and Wolfsberg. SF6 cannot scavenge thermal hydrogen atoms and its effects are attributable entirely to a competition with HCl for electrons.

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Tài liệu tham khảo

1964, Can. J. Chem., 42, 1906, 10.1139/v64-283

1966, J. Chem. Phys., 45, 3364, 10.1063/1.1728115

1961, Phys. Rev., 121, 1043, 10.1103/PhysRev.121.1043

1957, J. Phys. Chem., 61, 1089, 10.1021/j150554a013

1964, J. Phys. Chem., 68, 3829, 10.1021/j100794a050

1963, J. Chem. Phys., 38, 109, 10.1063/1.1733447

1952, Discussions Faraday Soc., 12, 30

1960, Can. J. Chem., 38, 407, 10.1139/v60-057

1965, Trans. Faraday Soc., 61, 1709, 10.1039/tf9656101709

1966, J. Chem. Phys., 44, 2192, 10.1063/1.1726998

1966, J. Chem. Phys., 45, 4634, 10.1063/1.1727547

1930, Phil. Mag., 10, 145, 10.1080/14786443009461565

1951, J. Am. Chem. Soc., 73, 523, 10.1021/ja01146a006

1963, J. Chem. Phys., 38, 465

1966, J. Am. Chem. Soc., 88, 28, 10.1021/ja00953a006

1926, Proc. Natl. Acad. Sci. U.S., 12, 35, 10.1073/pnas.12.1.35

1967, Can. J. Chem., 45, 3079, 10.1139/v67-498

1959, Phys. Rev., 114, 1028, 10.1103/PhysRev.114.1028

1963, Advan. Electron. Electron Phys., 18, 67, 10.1016/S0065-2539(08)60834-3

1966, J. Chem. Phys., 44, 1870, 10.1063/1.1726956

1961, J. Chem. Phys., 34, 1494, 10.1063/1.1701034

1964, Z. Naturforsch., 19a, 727

1964, Trans. Faraday Soc., 60, 1042, 10.1039/TF9646001042

1964, J. Phys. Chem., 68, 761, 10.1021/j100786a008

Thông tin
Thông tin xuất bản

Journal of Chemical Physics

Tập 48 Số 3

1235-1241

Thông tin tác giả