Radium hydroxide

Radium hydroxide
Identifiers
CAS Number	98966-86-0 ;
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

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]

Synthesis

A reaction of radium metal with water:^[3]

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.^[4]

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).

References

^ Brown, Paul L.; Matyskin, Artem V.; Ekberg, Christian (1 June 2022). "The aqueous chemistry of radium". Radiochimica Acta. 110 (6–9): 505–513. doi:10.1515/ract-2021-1141. ISSN 2193-3405. S2CID 248301187.
^ Matyskin, Artem V.; Brown, Paul L.; Ekberg, Christian (2019). "Weak barium and radium hydrolysis using an ion exchange method and its uncertainty assessment". Journal of Chemical Thermodynamics. 128: 362–371. Bibcode:2019JChTh.128..362M. doi:10.1016/j.jct.2018.08.037. S2CID 105458974.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^ "Alkaline Earth Hydroxide - an overview | ScienceDirect Topics". ScienceDirect. Retrieved 8 June 2023.
^ Schweitzer, George K.; Pesterfield, Lester L. (14 January 2010). The Aqueous Chemistry of the Elements. Oxford University Press. p. 448. ISBN 978-0-19-974219-6. Retrieved 8 June 2023.

[1] Brown, Paul L.; Matyskin, Artem V.; Ekberg, Christian (1 June 2022). "The aqueous chemistry of radium". Radiochimica Acta. 110 (6–9): 505–513. doi:10.1515/ract-2021-1141. ISSN 2193-3405. S2CID 248301187.

[2] Matyskin, Artem V.; Brown, Paul L.; Ekberg, Christian (2019). "Weak barium and radium hydrolysis using an ion exchange method and its uncertainty assessment". Journal of Chemical Thermodynamics. 128: 362–371. Bibcode:2019JChTh.128..362M. doi:10.1016/j.jct.2018.08.037. S2CID 105458974.{{cite journal}}: CS1 maint: multiple names: authors list (link)

[3] "Alkaline Earth Hydroxide - an overview | ScienceDirect Topics". ScienceDirect. Retrieved 8 June 2023.

[4] Schweitzer, George K.; Pesterfield, Lester L. (14 January 2010). The Aqueous Chemistry of the Elements. Oxford University Press. p. 448. ISBN 978-0-19-974219-6. Retrieved 8 June 2023.

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