Nasr Hussein El-Hammamy, Marwa Nasr El-Hammamy and Haitham Ahmed El-Araby
The Zwanzig theory of dielectric friction was applied to sodium diethyldithiocarbamate and alkali metal ions (Li+, K+, Rb+ and Cs+) in different pure solvents at 25° C. It was found that the value of (ri) obtained from the slope increases with increasing of the size from Na+ ion to diethyldithiocarbamate ion (DDC-) However, the value of (ri) obtained from the intercept decreases with increasing the size from Na+ ion to (DDC-) ion. The same trend is exist in case of alkali metal ions (Li+, K+, Rb+ and Cs+) where the value of (ri) obtained from the intercept decreases with increasing the size from Li+ to Cs+ ions but, The value of (ri) obtained from the slope increases with increasing of the size from Na+ to Cs+ ions. Such differences were investigated and discussed on the basis of the assumptions of Zwanzig theory. There was a scattering of the resulting points around the straight lines for the given ions in different solvents. The scattered values may be attributed to certain specific factors such as the uncertainty in the values of the relaxation time (τ) and solvation which are ignored in the continuum model and these play an important role in determining ionic mobility
