Determination of the Activity of Sodium in Sodium-Lead Alloys at High Temperatures

Abstract

The activity of sodium in sodium-lead alloys was determined by the concentration cell method. The emf of cells Na (pure)/Na+/Na in Pb was directly measured up to 820~ using alumina containers impregnated with Na2CO~ in an argon atmosphere. Results were converted to activities and extrapolated to 1010~ To check the extrapolation, emf's of cells of the type Na(a,) in Pb/Na+/Na(a~) in Pb were measured up to I010~ The a~/a, ratios calculated from the measurements were compared with those obtained by extrapolation. Fair agreement was found.) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 128.171.57.189 Downloaded on 2015-06-14 to IP ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 128.171.57.189 Downloaded on 2015-06-14 to IP

Chronopotentiometric Analysis in Fused Lithium Chloride-Potassium Chloride

“…Potentiometry (9,12,17,20) and polarography (1,2,5, IS, 14) have been applied to analysis in molten systems.…”

Sodium-Aluminum Equilibria in Cryolite-Alumina Melts

“…This cell was operated at 930 ~ 958~ and the sodium content of the lead layer built up to 11-12%. This corresponds to a sodium activity of 0.55 (19), which is equal to the value of aL at 945~176 Sodium activity at the cathode cannot exceed aL and any sodium produced beyond this point is free to escape. Since Fischer's pot was run under conditions representative of industrial operation, his data indicate that his pot as well as normal industrial pots liberate some sodium at the cathode.…”

“…The determination of the equilibrium activity of sodium in lead, in the presence of aluminum and cryolite melts, consisted of: (a) determination of the equilibrium concentration of sodium in lead after reaction; and (b) measurement of the activity of sodium in lead at various concentrations and temperatures in a separate study (19).…”

“…To overcome this difficulty lead was used as an auxiliary sodium "sink," and the concentration of sodium was determined in the lead phase rather than in the aluminum phase. From this, the sodium activity can be obtained (19).…”

“…The data from Table I were used to calculate EL [equation (II)]. The equilibrium activities of sodium in lead were determined from the corresponding concentrations (19). Values of p0 for Sodium used to calculate aL were obtained from the following expression log P(mm) = --5567/T -0.5 log T + 9.235 (26) (IV) These results are given in Table II.…”