Abstract
The conductivity and pH of azrechtic acid (ARA), a polyelectrolyte obtained from the electrodialysis of gum azadirechta indica have been investigated under different experimental conditions. The plot of equivalent conductivity A versus βC (phoreogram) is much steeper than for a comparable simple electrolyte. The phoreogram is strongly concave upward. It is shown that the conductivity is largely due to the hydrogen counterions. The equivalent conductivity has been expressed by the equation Ξ = KC^b^ where K and b are constants, K = 18.2 and b = β0.1452. The conductivity further follows the equation Ξ βΒ° Ξ = ββC/(A + BβC), ΞΒ° is the equivalent conductivity of ARA at infinite dilution and equals 73.5, A = 8.4 Γ 10^β4^ and B = 1.831 Γ 10^β2^. The degree of dissociation has been determined from measurement of electrical conductivity and pH. A discrepancy in the results has been tentatively explained. The degree of dissociation decreases with the concentration of ARA. It is noted that the conductance of an ARAβelectrolyte mixture is 5β12% higher than the calculated value. The pH of ARA with dilution follows the equation pH = D + E log C, where D = 2.96 and E = β0.85. It has been further shown that the pH with dilution also follows the expression pH = A~1~C^a^, where A~1~ = 2.96 and a = β0.1009.