Thermodynamics Studies Of Zinc Exchange On Calcium Saturated Soils Of Southeastern Nigeria Of Coastal Plain Sand Origin

ABSTRACT 

Cation exchange reaction is one of the numerous reactions that occur in soils. It is the reaction between exchangeable cations which takes place when one of soil solution cationrep1aces one of the cations held loosely on a charge surface (soil colloids). Example: Ca-soil (s) + Zn2 ' Ca + Zn - soil(s) (13 t where (s) and (aq) refer to soil exchange surface and soil solution respectively. This exchange reaction can only take place when the soil solution is not in equilibrium with a soil colloid and the extent it can occur on a soil colloid depends on the cation exchange capacity (CEC) of the soil, Cation exchange reation is a rapid, reversible reaction, exchanging equal cation charge and controls the availability of a particular nutrient to a crop since crops take up nutrients that are mainly in the soil solution. Cation exchange reaction are affected by concentration of cation in solution and the lyotropic series.