AbstractThe complex formation of uranyl ion withp‐methylaminophenol sulfate has been studied polarographically over thepHrange 1.5 to 4.7.A 1‐electron reversible reduction wave was observed in thispH range. AtpH. higher than 4.7, a reduction wave of complexing agent was produced.The diffusion current is proportional to the concentration of uranyl ion from 2.0×10−4Mto 5.1×10−3M. The diffusion current constant has been found to be 1.54±0.03, and the diffusion coefficient (7.96±0.2)×10−Gsq. cm. per second.Two hydrogen ions, in thepH range of 1.5 to 21, and one hydrogen ion, in thepH. range of 3.4 to 4.7, were consumed respectively by the reduction of three uranyl ions. AtpH 2.6 to 4.7, U(V) had one ligand l