Sodium hexachloroplatinate
Sodium hexachloroplatinate(IV), the sodium salt of chloroplatinic acid, is an inorganic compound with the formula Na2[PtCl6], consisting of the sodium cation and the hexachloroplatinate anion. As explained by Cox and Peters, anhydrous sodium hexachloroplatinate, which is yellow, tends to form the orange hexahydrate upon storage in humid air. The latter can be dehydrated upon heating at 110 ºC.[1]
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| Names | |
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| Other names
Sodium chloroplatinate Disodium platinum hexachloride | |
| Identifiers | |
3D model (JSmol) |
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| ECHA InfoCard | 100.037.242  |
PubChem CID |
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CompTox Dashboard (EPA) |
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| Properties | |
| Na2PtCl6 | |
| Molar mass | 453.7742 g/mol (anhydrous) 561.86588 g/mol (hexahydrate) |
| Appearance | Orange crystalline solid |
| Density | 2.5 g/cm³ |
| Melting point | 110 °C (230 °F; 383 K) |
| Soluble | |
| Hazards | |
EU classification (DSD) (outdated) |
Toxic (T) |
| R-phrases (outdated) | R25, R41, R42/43 |
| S-phrases (outdated) | S22, S24, S26, S36/37/39, S45 |
| Related compounds | |
Other anions |
Sodium hexafluorophosphate Sodium hexafluoroaluminate |
Other cations |
Potassium hexachloroplatinate Ammonium hexachloroplatinate |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
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| Infobox references | |
Preparation and reactions
Sodium hexachloroplatinate is obtained as an intermediate in the preparation of Pt complexes, often starting with the dissolution of platinum in aqua regia, giving hexachloroplatinic acid, which is then reacted with sodium chloride and evaporated, leaving the salt behind.[2]
- Pt + 4 HNO3 + 6 HCl → H2[PtCl6] + 4 NO2 + 4 H2O
- H2[PtCl6] + NaCl → Na2[PtCl6] + 2 HCl
The compound can be converted back to platinum metal via conversion to the ammonium salt followed by thermal decomposition, allowing platinum metal to be recovered from laboratory residues.
- Na2[PtCl6] + 2 NH4Cl → (NH4)2[PtCl6] + 2 NaCl
- 3 (NH4)2[PtCl6] → 3 Pt + 2 N2 + 2 NH4Cl + 16 HCl
Reference
- Cox, Lawrence E.; Peters, Dennis G. (1972). Disodium Hexachloroplatinate(IV). Inorganic Syntheses. pp. 173–176. doi:10.1002/9780470132449.ch34. ISBN 9780470132449.
- Kauffman, George B.; Teter, Larry A. (1963). Recovery of Platinum from Laboratory Residues. Inorganic Syntheses. 7. pp. 232–236. doi:10.1002/9780470132388.ch61. ISBN 9780470132388.