AbstractComposition and stability of palladium‐Nitroso R Salt chelate, lanthanum, thorium, uranium and palladium chelates of Thoron, lanthanum‐Chromotrope 2 B chelate and palladium‐Chrome Azurol S chelate have been reported. The range of stability of the chelates with pH have also been determined. The use of Chrome Azurol S, Chromotrope 2 B, Murexide, Thoron, Quinizarin sulphonic acid, and gallocyanine in the complexometric determination of thorium against EDTA has also been rep