Radium hydroxide

The Uses of Radium hydroxide

Radium hydroxide (RaOH) is the most soluble of all the hydroxides of the alkali earth metals. It is formed when radium reacts with water (2Ra + 2H2O → 2RaOH + H2↑).

Preparation

Radium hydroxide may be prepared by the reaction of BeO added to water. The reaction is violent with evolution of considerable heat:
RaO＋H2O→Ra(OH)2
It may also be prepared by reacting the nitrate with NaOH in solution. There is no record of this salt actually having been prepared. However, it is expected that beryllium hydroxide is soluble so that the solution needs to be evaporated at a low temperature (with vacuum) in the presence of ethanol to crystallize the salt, Be(OH)2·8H2O. The crystals are then washed in cold ethanol to remove traces of sodium ions and then dried. The crystals are strongly absorbent of carbon dioxide from the air, forming the carbonate as an end-product.