Observations on Ion Separation in Dilute Solutions by Freezing

Publisher Website
Google Scholar
Abstract
The electrification produced by the freezing of dilute aqueous solutions was studied in an attempt to determine (1) the factors governing which ion is rejected by the ice phase, and (2) the interrelationship of concentration, freezing rate, observed potential, and ionic segregation between the phases for sodium chloride, which appears to be typical. It was shown that ionic rejection is not on the basis of ion size alone, though this is doubtless important. Ion segregation increases with freezing rate over the range studied. Observed interphase potential goes through a maximum as concentration is increased; at a given concentration, the potential also goes through a maximum as freezing rate increases. The freezing rate corresponding to this maximum potential is lowest in the vicinity of the concentration yielding the highest potential. The effects of concentration and freezing rate on the potential-time curves were also noted. Chemical analyses of the phases was complicated by self-electrolysis of the solution. Physical interpretations of some of these phenomena are offered.

This publication has 4 references indexed in Scilit: