Chemical potentials and related thermodynamics of sodium-ammonia solutions

Data on the temperature and composition dependence of the chemical potential of Na in Na–NH₃ solutions obtained from an electrochemical cell are reported. The cell used a bridge electrode of sodium beta‐alumina. A variety of thermodynamic parameters are calculated and estimates are given for the critical exponents α, γ, and δ. Particular attention is paid to the concentration fluctuations ${\mathrm{〈(\Delta \; x)}}^2〉$ which provide indications of clustering in these and other solutions.