Influence of the acidity of the Iodous acid solution system on the kinetics of the disproportionation reaction

Abstract

Influence of the acidity of the iodous acid (HOIO) solution system on the kinetics disproportionation reaction is examined in aqueous sulfuric acid solution (0.125 moldm-3). The disproportionation reaction rate constants were determined at 285, 291, 298 and 303 K based on data obtained under stationary conditions. The calculated rate constants increase with increasing temperature for different values of iodous acid and iodate concentrations. The average activation energy of 46 kJmol-1 was determined for the chosen temperature interval, by a graphical method. The values of pseudo-equilibrium concentrations of kinetically important and catalytic species H + , H 2 OI + i IO 3-in the disproportionation reaction were determined for the given experimental conditions based on the equilibrium dissociation reactions of sulfuric and iodous acids in the quasi-stationary state. The estimated values of sulfuric and iodous acid are predominant and higher than the concentration of the protonated ion of H 2 OI + .

Keywords

• disproportionation reaction
• iodous acid
• activation energy
• rate constants
• kinetics