Abstract
Adsorption reactions are of utmost importance to understand the availability of nutrients to the plants. The thermodynamic parameters (DeltaGdegrees, DeltaHdegrees and DeltaSdegrees) or the adsorption of manganese on six soils were calculated at two temperatures, i.e., 25 and 35degreesC. The adsorption data, fitted into the linear form of the Langmuir equation, made it possible to evaluate the adsorption maxima and binding energy. The values of DeltaGdegrees, DeltaHdegrees and DeltaSdegrees were found to be negative in a the soils indicating the exothermic and spontaneous nature of the adsorption reaction.