CONSIDERATION OF THE THERMODYNAMIC STABILITY OF IODINE SPECIES IN THEBRAY-LIEBHAFSKY REACTION

The standard free energy of formation of IO. and HIO2 in water solutio n at 298 K are estimated to be Delta G(IO .)(0) = 120 kJ/mol and Delta G(HIO2) = -75 kJ/mol. Values of standard reduction potentials for hal f-reaction HIO2 + 2H(+) + 2e(-) ---> HIO + H2O, IO. + H+ + e(-) --> HI O, IO3- + 3H(+) + 2e --> HIO2 + H2O and HIO2 + H+ + e --> IO. + H2O ar e calculated to be E-0 = 1.35 V, E-0 = 2.3 V, 0.92 V and E-0 = 0.4 V. Energetic requirements during the process of oxidation of iodine in ac idic media are introduce as an important criteria in examination of th e models of the Bray-Liebhafsky reaction mechanism.