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| The anhydrous form can be produced by heating the tetrahydrate to 350 °C. If the anhydrous is heated to 820 °C, it decomposes to hafnium(IV) oxide, sulfur oxides, and ]. The mechanism of decomposition has not been fully elucidated.<ref name="decomp" /> | The anhydrous form can be produced by heating the tetrahydrate to 350 °C. If the anhydrous is heated to 820 °C, it decomposes to hafnium(IV) oxide, sulfur oxides, and ]. The mechanism of decomposition has not been fully elucidated.<ref name="decomp" /> | ||
| Various hydrolyzed derivatives of hafnium(IV) oxide, such as {{chem2|Cl0.6·nH2O}}.<ref>{{cite journal |author1=Ali Kalaji |author2=L. Soderholm |title=Aqueous Hafnium Sulfate Chemistry: Structures of Crystalline Precipitates |journal=Inorganic Chemistry |date=2014 |volume=53 |issue=20 |pages=11252–11260 |doi=10.1021/ic501841e |language=en}}</ref> | Various hydrolyzed derivatives of hafnium(IV) oxide, such as {{chem2|Cl0.6·nH2O}} are known.<ref>{{cite journal |author1=Ali Kalaji |author2=L. Soderholm |title=Aqueous Hafnium Sulfate Chemistry: Structures of Crystalline Precipitates |journal=Inorganic Chemistry |date=2014 |volume=53 |issue=20 |pages=11252–11260 |doi=10.1021/ic501841e |language=en}}</ref> | ||
| ==References== | ==References== | ||
Revision as of 18:28, 20 December 2024
| Names | |
|---|---|
Other names
| |
| Identifiers | |
| CompTox Dashboard (EPA) | |
| Properties | |
| Chemical formula | Hf(SO4)2 |
| Molar mass | 370.62 g/mol (anhydrous) |
| Appearance | White solid |
| Density | 4.86 g/cm |
| Melting point | 350 °C (662 °F; 623 K) (decomposition) |
| Solubility in water | Soluble |
| Structure | |
| Crystal structure | Orthorhombic |
| Coordination geometry | 8 (hafnium) |
| Related compounds | |
| Other anions | Hafnium(IV) nitrate |
| Other cations | Zirconium(IV) sulfate |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa). Infobox references | |
Hafnium(IV) sulfate is describes the inorganic chemical compounds with the formula Hf(SO4)2·nH2O, where n can range from 0 to 7. It commonly forms the anhydrous and tetrahydrate forms, which are both white solids.
Structure
Anhydrous hafnium(IV) sulfate consists of a polymeric network of sulfate-bridged hafnium atoms. It is isomorphous with zirconium(IV) sulfate.
Hafnium(IV) sulfate tetrahydrate is isomorphous with zirconium(IV) sulfate tetrahydrate and consists of repeated sheets of Hf(SO4)2(H2O)4, where the sulfate ligands are bidentate.
Preparation and properties
The tetrahydrate is produced by the reaction of hafnium metal or hafnium(IV) oxide with concentrated sulfuric acid followed by evaporation of the solution:
- Hf + 2 H2SO4 → Hf(SO4)2 + 2 H2
The anhydrous form can be produced by heating the tetrahydrate to 350 °C. If the anhydrous is heated to 820 °C, it decomposes to hafnium(IV) oxide, sulfur oxides, and oxygen. The mechanism of decomposition has not been fully elucidated.
Various hydrolyzed derivatives of hafnium(IV) oxide, such as [Hf18O10(OH)26(SO4)12.7(H2O)20]Cl0.6·nH2O are known.
References
- ^ I.J. Bear; W.G. Mumme (1970). "The preparation and characterization of phases in the Hf(SO4)2H2O system". Journal of Inorganic and Nuclear Chemistry. 32 (4): 1159–1164. doi:10.1016/0022-1902(70)80110-5.
- ^ H.A. Papazian; P.J. Pizzolato; R.R. Orrell (1972). "The Thermal Decomposition of Aluminum Sulfate and Hafnium Sulfate". Thermochimica Acta. 4 (2): 97–103. doi:10.1016/S0040-6031(72)80023-6.
- Ali Kalaji; L. Soderholm (2014). "Aqueous Hafnium Sulfate Chemistry: Structures of Crystalline Precipitates". Inorganic Chemistry. 53 (20): 11252–11260. doi:10.1021/ic501841e.
| Hafnium compounds | |
|---|---|
| Hf(II) | |
| Hf(III) | |
| Hf(IV) | |