Revista de Ciencias Químicas

Spectrophotometric Study on Kinetics and Thermodynamics of Adsorption and Catalytic Transformation of K2Cr2O7 to K2CrO4 by Natural Hermit Crab Shell Powder

Abstract

G Dong, Y Zhu, Y Zhang, H Shan, J Xu, S Xin

The adsorption and transformation of K2Cr2O7 at natural hermit crab shell powder was studied by UV-visible spectrophotometry. K2Cr2O7 is adsorbed at natural hermit crab shell powder, and follows the Freundlich adsorption model with the adsorption constant of KF=888.8 and adsorption free energy change of 16.83 kJ.mol-1. The adsorbed K2Cr2O7 is catalytically transformed into K2CrO4 in moderate conditions by natural hermit crab shell powder with the apparent first-order rate constant of 0.0219 s-1, and equilibrium constant of K=2.27×1012 M-1.