Sodium stannate

Sodium stannate

Names
IUPAC name Sodium hexahydroxostannate(IV)
Other names disodium hexahydroxyltin Sodium stannate(IV) sodium stannate–3–water sodium tin(IV) oxide hydrate
Identifiers
CAS Number	12027-70-2
3D model (JSmol)	Interactive image
ChemSpider	145444^Y
ECHA InfoCard	100.031.554
EC Number	234-724-5
PubChem CID	131868867
UNII	NJ7C1V83KG
CompTox Dashboard (EPA)	DTXSID70891881
InChI InChI=1S/2Na.6H2O.Sn/h;;6*1H2;/q2*+1;;;;;;;+4/p-6 Key: PMPBLIIMRRPPEO-UHFFFAOYSA-H
SMILES [OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[Na+].[Na+].[Sn+4]
Properties
Chemical formula	H6Na2O6Sn
Molar mass	266.73 g/mol
Appearance	Colorless or white solid
Density	4.68 g/cm^3
Boiling point	N/A
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H314, H315, H319, H335, H412
Precautionary statements	P260, P261, P264, P271, P273, P280, P301+P330+P331, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P310, P312, P321, P332+P313, P337+P313, P362, P363, P403+P233, P405, P501
NFPA 704 (fire diamond)	2 0 0
Flash point	57 °C (135 °F; 330 K)
Autoignition temperature	N/A
Lethal dose or concentration (LD, LC):
LD50 (median dose)	2132 mg/kg [Mouse]
Safety data sheet (SDS)	[1][1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Sodium stannate, formally sodium hexahydroxostannate(IV), is the inorganic compound with the formula Na₂[Sn(OH)₆]. This colourless salt forms upon dissolving metallic tin or tin(IV) oxide in sodium hydroxide and is used as a stabiliser for hydrogen peroxide.[2] In older literature, stannates are sometimes represented as having the simple oxyanion SnO₃^2−,[3] in which case this compound is sometimes named as sodium stannate–3–water and represented as Na₂SnO₃·3H₂O, a hydrate with three waters of crystallisation.[1] The anhydrous form of sodium stannate, Na₂SnO₃, is recognised as a distinct compound with its own CAS Registry Number,[4] 12058-66-1 , and a distinct material safety data sheet.[5]

Alkali metal stannate compounds are prepared by dissolving elemental tin in a suitable metal hydroxide, in the case of sodium stannate by the reaction:[6]

Sn   +   2 NaOH   +   4 H₂O   →   Na₂[Sn(OH)₆]   +   2 H₂

A similar reaction occurs when tin dioxide is dissolved in base:

SnO₂   +   2 NaOH   +   2 H₂O   →   Na₂[Sn(OH)₆]

The anhydrous form can also be prepared from tin dioxide by roasting with sodium carbonate in a mixed carbon monoxide / carbon dioxide environment:[7]

SnO₂   +   Na₂CO₃   →   Na₂SnO₃   +   CO₂

The anion is a coordination complex that is octahedral in shape, similar to most stannates, such as the hexachlorostannate anion [SnCl₆]^2−. The Sn—O bond distances average 2.071 Å.[8]

See also

• Sodium carbonate
• Sodium silicate
• Sodium germanate

References

1. "Material Safety Data Sheet – sodium stannate trihydrate MSDS". Science Lab. 21 May 2013. Archived from the original on 1 June 2012. Retrieved 1 June 2017.
2. Clark, John D. (1972). Ignition! An Informal History of Liquid Rocket Propellants. Rutgers University Press. ISBN 0813507251.
3. Similarly, stannites are sometimes represented with the anion SnO₂^2−
4. National Center for Biotechnology Information (2017). "Sodium Stannate". PubChem. Retrieved 1 June 2017.
5. "Sodium Stannate MSDS" (PDF). Santa Cruz Biotechnology. 14 June 2011. Retrieved 1 June 2017.
6. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0750633654.
7. Zhang, Yuanbo; Su, Zijian; Liu, Bingbing; You, Zhixiong; Yang, Guang; Li, Guanghui; Jiang, Tao (2014). "Sodium stannate preparation from stannic oxide by a novel soda roasting–leaching process". Hydrometallurgy. 146: 82–88. Bibcode:2014HydMe.146...82Z. doi:10.1016/j.hydromet.2014.03.008.
8. Jacobs, Herbert; Stahl, Rainer (2000). "Neubestimmung der Kristallstrukturen der Hexahydroxometallate Na₂Sn(OH)₆, K₂Sn(OH)₆ und K₂Pb(OH)₆". Z. Anorg. Allg. Chem. (in German). 626 (9): 1863–1866. doi:10.1002/1521-3749(200009)626:9<1863::AID-ZAAC1863>3.0.CO;2-M.