Suraj Prasad
Last Activity: 10 Years ago
There are many chemical equilibria. Due the acidity constant of the presents species in soil, there is in your aqueous sample, molecular species and dissociated species, that changes with pH. For example, acetic acid present a pKa equal to 4.72. In pH 4.72 there is 50% of acetic acid (HA) specie and 50% of acetate ion (A-) specie. In pH<4.72 increase the molecular specie (HA) and pH>4.72 the opposite. Therefore, depending of the pH, you will have lower or higher condutivity, because you will may have molecular (low condutivity) or dissociated (high condutivity) species. The redox potencial also changes with type of specie, molecular or dissociated (charged).