Rubidium Cerium Selenates

Preparation and properties correspond to LiLa(Se04)2 6H20, see p. 504. The pycnometrically determined density is 3.16 g/cm at 25 C. On heating RbCe(Se04)2 H20 is formed at 110°C [4]. 

The thermal decomposition of RbCe(Se04)2 4H20 was followed by TG at a heating rate of 5.2 K/mln, and by DTA (diluted to 20% in a-Al203) at a heating rate of 9 K/min. Reactions and corresponding temperature ranges observed in the TG and DTA curves  

Although the TG curves given do not show any evidence of the formation of intermediate compounds at 333 to 480°G, the reduction of selenate to selenite is assumed simultaneously with the oxidation of Oe to Oe, resulting in 0e02. In the last step, Rb28e04 Is partly evaporated and the residue contains 0e02 and 54.5% of the theoretical amount of Rb20 [5]. 

When RbCe(Se04)2-6H20 is heated to 110°C, the monohydrate Is formed. Its pycnometri-cally determined density Is 3.98 g/cm at 25°C. It Is dehydrated at 130 to 150°C [4]. 

---