Kinetics of uranyl ion polymerization in the presence of ammonium hydroxide

Kinetics of the polymerization of UO2 2+ ion to UO2[(OH)2UO2]4 2+ in the ammonia-uranyl nitrate system has been studied. The deepening of the color formed with the addition of ammonia made it possible to estimate spectrophotometrically the concentration of the formed UO2[(OH)2UO2]4 2+ ions in the solution at 420.6 nm. The effects of pH, temperature as well as the concentration of uranyl ion have been investigated. The reaction rate equation for the polymerization reaction is presented. Linear dependencies of logarithm of the apparent reaction-rate constant on both pH and the reverse of temperature were observed.