Thermal diffusion of alkali bromides

The molar entropies (or heats) of transport of dilute aqueous alkali bromide solutions have been measured by the potentiometric method using the silver, silver bromide thermocell at a mean temperature of 25°C and over a concentration range of 5×10^–4 to 0.1M. Experimental results were extrapolated to infinite dilution to obtain the standard molar entropies of transport. The limiting behavior observed is compared with theory based on the electrostatic model.The standard transported entropy of Br^– was also derived by extrapolating the steady-state thermoelectric powers to infinite dilution. The absolute ionic entropies of transport of alkali metal ions have been estimated based on Gurney's scale. The results obtained are compared with that derived f¹/om the previous work on alkali chlorides.