Radium hydroxide

Radium hydroxide is an inorganic compound of radium, hydrogen, and oxygen with the chemical formula Ra(OH)₂.^[1] Stability constant of aqueous RaOH⁺ ion pair at zero ionic strength is equal to 5.^[2]

Radium hydroxide

Identifiers
CAS Number	98966-86-0 Y
3D model (JSmol)	Interactive image
ChemSpider	66737595
InChI InChI=1S/2H2O.Ra/h2*1H2;/q;;+2/p-2 Key: ARVNHJBMBBFPCP-UHFFFAOYSA-L
SMILES [Ra+2].[O-H].[O-H]
Properties
Chemical formula	H2O2Ra
Molar mass	260 g·mol−1
Appearance	colorless crystals
Solubility in water	soluble
Related compounds
Related compounds	Barium hydroxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Synthesis

• A reaction of radium metal with water:^{[citation needed]}

Ra + 2H₂O → Ra(HO)₂ + H₂

• The reaction of radium oxide and water can also generate radium hydroxide, and the reaction releases a lot of heat:^{[citation needed]}

RaO + H₂O → Ra(HO)₂

• The compound can also be prepared by reacting radium nitrate with NaOH in solution.^{[citation needed]}

Physical properties

Radium hydroxide forms colorless crystals that dissolve in water better than does barium hydroxide, and has more basic properties.

The compound forms a hydrate of the composition Ra(OH)₂·8H₂O.^[3]

Radium hydroxide is a caustic, toxic, and corrosive substance. It is significantly more toxic than barium hydroxide (Ba(OH)₂) and strontium hydroxide (Sr(OH)₂).