Abstract
The free energy (Gibbs) of formation of 
, 
, and 
and their activities in molten salt solutions at temperatures between 823° and 973°K have been determined by using the following galvanic cells
and
The nitrogen electrode used in cell (II) has been proved to have a Nernstian behavior by studying the dependence of emf on the partial pressure of nitrogen. The activity coefficients of 
and 
in molten salts have been found to decrease with increasing concentration.