A NEW CHEMICAL OSCILLATOR IN GROUP-VI-A - NA2S2O8-KSCN-CUSO4 SYSTEM

A new chemical oscillator in group VI A was first discovered in the Na 2S2O8-KSCN-CuSO4 system, In a batch reactor the reaction displays sing le-peak behavior in redox potential, In a continous stirring tank reac tor (CSTR) the reaction displays sustained oscillations both in redox potential and pH. Depending upon the composition and flow rate of the Input stream, we find either a low pH (pH = 1 similar to 4) steady sta te, sustained oscillation (pH = 5 similar to 6), or a high pH (pH = 9 similar to 10) steady state, The reaction system still displays oscill ation behavior when the reductant (SCN-) is in excess, The oscillatory region is very narrow in NaOH concentration (3 x 10(-3) mol/L < [NaOH ] < 1 x 10(-2) mol/L).