Sodium stannate

Sodium stannate
White powder of 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
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.031.554 Edit this at Wikidata
EC Number
  • 234-724-5
UNII
  • InChI=1S/2Na.6H2O.Sn/h;;6*1H2;/q2*+1;;;;;;;+4/p-6
    Key: PMPBLIIMRRPPEO-UHFFFAOYSA-H
  • [OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[Na+].[Na+].[Sn+4]
Properties
H6Na2O6Sn
Molar mass 266.73 g/mol
Appearance Colorless or white solid
Density 4.68 g/cm3
Boiling point N/A
Hazards
GHS labelling:
GHS05: CorrosiveGHS07: Exclamation mark
Danger
H314, H315, H319, H335, H412
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)
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
2
0
0
Flash point 57 °C (135 °F; 330 K)
N/A
Lethal dose or concentration (LD, LC):
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).

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 SnO32−,[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]

  1. ^ a b "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 SnO22−
  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.