Azosulfonamide rhodanines are widely used as analytical reagents. They are capable of forming chelates with many of metal ions. The formed chelates are distinguished by their stability due to the formation of chelate ring. From the structural point of view, these were considered as metal indicators since they posses functional groups capable of chelate formation joined directly to the central metal ions.In the present investigation, proton-ligand stability constant, pKH, of azosulfonamide rhodanine compounds will be determined potentiometrically in 20% (v/v) DMF- water mixture. The...