Conductance measurements of murexide or ammonium purpurate solutions were made at 30° + 0.05°C. using a Serfass conductivity bridge. Ostwald’s dilution law was found to be inapplicable; equivalent conductance at infinite dilution and the classical and thermodynamic dissociation constants were computed by various methods applicable for systems involving ion association. The following physico-chemical constants of murexide were calculated :-
Thermodynamic dissociation constant.
Ionic mobility of purpurate ion.