“…40 g (Amberlite IR 120) resin was used also for the getting CMC acid, (HCMC), prepared from the low density of 1 % NaCMC solution and then the more concentrated solution of HCMC was prepared by evaporating it under vacuum at 40 °C. The concentration of this stock solution was determined by electrometric pH titration and was found to be 2.7 × 10 -2 eq g/L referred to COOH, from which the rest of the desired concentrations were prepared [5]. The equivalent weight of dried CMC acid was found to be 281.6 g/eq by potentiometric titration.…”