[en] The kinetics of the reaction of uranium(VI) with 8-quinolinol and 8-hydroxy-5-quinolinesulfonate under the conditions of 1:1 chelate formation in the pH range 3.6-4.6 at different temperatures (20-30degC) and ionic strength I = 0.1 moldm^-3 (KNO₃) have been studied. A dual path mechanism involving both UO₂(aq)²⁺ and UO₂(OH)(aq)⁺ and the partially deprotonated ligand (LH, LH^-) is consistent under the experimental conditions. The different rate constants under the condition of equilibrium have been determined. The results conform to k_obs/B = k₁[H⁺] + k₂K_h; where B = (1/Q) + K_a(1)T_U / ([H⁺] + K_a(1)) (K_h + [H⁺]); K_h = hydrolysis constant of UO₂(aq)²⁺; K_a(1) = first deprotonation constant of the ligand, LH₂ (charges are omitted); k₁ and k₂ are the second order forward rate constants of UO₂(aq)²⁺ and UO₂(OH)(aq)⁺ respectively and Q is the equilibrium constant of the reaction, UO₂²⁺ + LH ↔ UO₂L⁺ + H⁺, where LH represents the partially deprotonated form of the ligand, 8-quinolinol and a similar reaction occurs for deprotonated 8-hydroxy-5-quinolinesulfonate (LH^-). Thermodynamic parameters for each of the steps have been determined. The results have been compared with those of recent findings in the interaction of cerium(VI) and iron(III) with these ligands. UO₂(aq)²⁺ has been argued to react through a dissociative interchange (I_d) mechanism and its characteristic water exchange rate has been found as a rough estimate. Similarly for UO₂(OH)(aq)⁺, a dissociative mechanism has been speculated. (author)