First Dissociation Constant of Succinic Acid from 0° to 50° G and Related Thermodynamic Quantities

The sensitivities of CH4 and CD4 differ by about 2 percent and are probably equal within the experimental uncertainty. The total ionization is apparently the same for CH4, CH3D, and CH?D2. The low value for CHD3 is not significant in view of the uncertainty in this spectrum. The difference in the total ionization of CH4 and CD4, however, is greater than the estimated error; and since the number of dissociation processes remains the same, the difference is probably a result of the lower probability of dissociating C—D bonds. Although our experimental results for CH3D are in good agreement with Turkevich et al. and with Evans, Bauer, and Beach, the different authors have used somewhat different assumptions in the interpretation of results. Although the assumptions used by Evans, Bauer, and Beach lead to nearly the same results in CH3D, their assumptions did not seem to be generally applicable to the three spectra CH3D, CH2D2, and CHD3, necessitating the different approach used in this work.