The Solid Solution between NaClO₃ and NaBrO₃ Revisited

Abstract

NaClO3 and NaBrO3 are believed to form a complete solid solution from RT to fusion. The unique solid phase can thus be written: NaClO3(1−x)-NaBrO3(x) with: 0 ≤ x ≤ 1. This study shows that at high temperatures, this statement might be valid. Nevertheless, up to 50 °C, probably up to 160 °C, and even higher temperatures, this is not true when the system is in thermodynamic equilibrium. A large miscibility gap exists at room temperature (RT). This gap could be reduced up to a complete disappearance by fast crystallization, for instance, spray-drying. The necessary conditions to access equilibrium, including homochirality, are also discussed.

Keywords

• solid solutions
• heterogeneous stable & metastable equilibria
• crystallization
• sodium chlorate
• sodium bromate