Abstract:
An amperometric method has been developed for continuous determination of iodine concentrations of the order of 10-5 molar.
Catalysis of the bromate-iodide and iodate-iodide reactions by carboxylate and phoshphate ions has been shown to occur. The rates of these reactions may be expressed:
-d(BrO⁻₃)/dt = k₀(H⁺)²(I⁻)¹(Br0⁻₃)¹ + kb(B⁻)¹(H⁺)²(I⁻)¹(BrO₃)¹
-d(IO⁻₃)/dt = k₀(H⁺)²(I⁻)²(IO⁻₃)¹ + kb(B⁻)¹(H⁺)²(I⁻)²(IO⁻₃)¹/1 + k'(I⁻)¹
The structure of the iodate ion in solution has been investigated. It has been concluded that the predominant species is the pyramidal IO-3 ion, and any aquated form is present to the extent of no more than one part in 108.
Previous studies of halate-halide and related reactions have been reviewed, and mechanisms have been postulated for these reactions on the basis of available information.