This paper is summarized with one of the applications of adsorption behavior; A UV-Vis method has been applied to survey the isotherm of adsorption. Results for experimental showed the applicability of Langmuir equation. The effect of temperature on the adsorption of cobalt (II) Complex by bentonite surface was studied. The results shown that the amount of adsorption was formed to increase, such as the temperature increase (Endothermic process). Cobalt (II) Complex has adsorption studies by bentonite surface at different pH values (1.6-10); these studies displayed an increase in adsorption with increasing pH. ΔG, ΔH, and ΔS thermodynamic functions of the cobalt (II) Complex for their adsorption have been calculated.

A charge transfer complex formed by interaction between the p-aminodiphenylamine (PADPA) as electron donor with iodine as electron acceptor in ethanol at 25 0 C as evidenced by color change and absorption. The spectrum obtained from complex PADPA -Iodine shows absorptions bands at 586 nm. All the variables which affected on the stability of complex were studies such as temperature, pH, time and concentration of acceptor. The linearity of the method was observed within a concentration rang (10-165) mg.L -1 and with a correlation coefficient (0.9996), while the molar absorbitivity and sandell sensitivity were (4643.32) L.mol -1 .cm -1 and (0.0943) µg.cm -2 , respectively. The adsorption of complex PADPA-I 2 was studied using adsorbent surfaces arundo plant. The dynamics of isotherm were studied according to experimental conditions of contact time, adsorbent weight, pH and particle size. The results showed the adsorption isotherm according to the Gils classification indicated L 1 , when the temperature (10,25) 0 C of plant, but S 2 at (37.5,50) 0 C for plant. Analytical techniques including UV-Vis. & FTIR were applied to characterize arundo. The values of Gibbs free energy, enthalpy ,entropy calculated from the thermodynamics of the process.