Complex Oligooscillatory Behavior in the Reaction of Chlorite with Thiocyanate

The reaction of chlorite and thiocyanate has been studied in the pH range 1-4. The stoichiometry of the reaction is 2ClO 2 - +SCN - +H 2 O→SO 4 2- +2Cl - +HOCN+H + . In excess ClO 2 - , ClO 2 (aq) is formed as a product at the end of the reaction. ClO 2 is formed from the reaction of excess ClO 2 - with HOCl:2Cl0 2 - +HOCl +H + →2ClO 2 +Cl - +H 2 O. At pH less than 4 and in excess SCN - , ClO 2 is formed as an intermediate but is totally consumed at the end of the reaction. The reaction is very complex with oligooscillatory behavior in which ClO 2 concentration goes through two maxima during the course of the reaction