Gibbs energies, enthalpies and entropies of transfer of cations from acetonitrile and N,N-dimethylformamide into water
Abstract
Gibbs energies of transfer from acetonitrile and N,N-dimethylformamide into water for the cations Li+, Na+, K+, Rb+, Cs+, Ag–, Tl+, Ba2+, Cu2+, Zn2+, Cd2+, and Pb2+ have been calculated from reversible polarographic half-wave potentials on the basis of the bis(biphenyl)chromium assumption. Gibbs energies of transfer for Ag+ and Hg2+ were obtained from the potentials of the respective M/Mn+(0.01 mol dm–3) electrodes. Good agreement was found with Gibbs energies of transfer obtained from the tetraphenylarsonium tetraphenylborate assumption. Reaction entropies for the systems Mn+/M(Hg) and entropies of transfer have been derived from measurements of the temperature coefficents of the polarographic half-wave potentials vs. Ag/Ag+(0.01 mol dm–3) electrodes kept at 25 °C employing the assumption of a negligible thermal diffusion potential. Enthalpies of transfer were obtained from the Gibbs energies and the entropies of transfer.