radium hydroxide
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| Name = Radium hydroxide
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| CASNo = 98966-86-0
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| ChemSpiderID = 66737595
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| StdInChI= 1S/2H2O.Ra/h2*1H2;/q;;+2/p-2
| StdInChIKey = ARVNHJBMBBFPCP-UHFFFAOYSA-L
| SMILES = [Ra+2].[O-H].[O-H]
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|Section2={{Chembox Properties
| Ra=1 | H=2 | O=2
| Appearance = colorless crystals
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| Solubility = soluble}}
|Section3={{Chembox Hazards
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|Section6={{Chembox Related
| OtherCompounds = Barium hydroxide
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Radium hydroxide is an inorganic compound of radium, hydrogen, and oxygen with the chemical formula {{chem2|Ra(OH)2}}.{{cite journal |last1=Brown |first1=Paul L. |last2=Matyskin |first2=Artem V. |last3=Ekberg |first3=Christian |title=The aqueous chemistry of radium |journal=Radiochimica Acta |date=1 June 2022 |volume=110 |issue=6–9 |pages=505–513 |doi=10.1515/ract-2021-1141 |s2cid=248301187 |language=en |issn=2193-3405|doi-access=free }} Stability constant of aqueous RaOH+ ion pair at zero ionic strength is equal to 5.{{Cite journal |last=Matyskin, Artem V.; Brown, Paul L.; Ekberg, Christian |date= 2019|title=Weak barium and radium hydrolysis using an ion exchange method and its uncertainty assessment |url=https://www.sciencedirect.com/science/article/pii/S0021961418303239 |journal=Journal of Chemical Thermodynamics |volume=128 |pages=362–371|doi= 10.1016/j.jct.2018.08.037|bibcode= 2019JChTh.128..362M|s2cid= 105458974|url-access=subscription}}
Synthesis
- A reaction of radium metal with water:{{Citation needed|date=November 2024}}
::{{chem2|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:{{cn|date=September 2023}}
::{{chem2|RaO + H2O -> Ra(HO)2}}
- The compound can also be prepared by reacting radium nitrate with NaOH in solution.{{cn|date=September 2023}}
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 {{chem2|Ra(OH)2*8H2O}}.{{cite book |last1=Schweitzer |first1=George K. |last2=Pesterfield |first2=Lester L. |title=The Aqueous Chemistry of the Elements |date=14 January 2010 |publisher=Oxford University Press |isbn=978-0-19-974219-6 |page=448 |url=https://books.google.com/books?id=-TNhhlGcCzwC&dq=%22Ra%28OH%292%22+solubility&pg=PA148 |access-date=8 June 2023 |language=en}}
Radium hydroxide is a caustic, toxic, and corrosive substance. It is significantly more toxic than barium hydroxide ({{chem2|Ba(OH)2}}) and strontium hydroxide ({{chem2|Sr(OH)2}}).