Difference between revisions of "Mercury sulfide"
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Mercury sulfide is resistant to the attack of most reagents, such as acids and bases. | Mercury sulfide is resistant to the attack of most reagents, such as acids and bases. | ||
| − | + | It will however react with oxidizing mixtures at high temperatures, such as acidified dichromate solutions in conc. sulfuric acid, at temperatures above 100-150 °C. | |
| − | :HgS + O<sub>2</sub> → Hg + SO<sub>2</sub> | + | However, mercury sulfide in cinnabar form will burn when ignited in air or a stream of pure oxygen, releasing [[sulfur dioxide]] and mercury vapors, which are very toxic and corrosive to many metals, like aluminium.<ref>https://www.youtube.com/watch?v=2pMAfEPEHbI</ref> |
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| + | : HgS + O<sub>2</sub> → Hg + SO<sub>2</sub> | ||
===Physical=== | ===Physical=== | ||
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==Preparation== | ==Preparation== | ||
| − | Mercury(II) sulfide can be created by adding elemental [[sulfur]] to [[mercury]] metal. Mercury sulfide is the | + | Mercury(II) sulfide can be created by adding elemental [[sulfur]] to [[mercury]] metal. [[Zinc]] powder is sometimes added to accelerate the reaction. Mercury sulfide is the main product of mercury disposal, as it is inert and safe to handle. |
By precipitating mercury salts with hydrogen sulfide or soluble sulfides usually the black polymorph is obtained. Heating in polysulfide solutions convert it into the red polymorph.<ref>[https://illumina-chemie.de/viewtopic.php?f=69&t=3336 https://illumina-chemie.de/viewtopic.php?f=69&t=3336]</ref> | By precipitating mercury salts with hydrogen sulfide or soluble sulfides usually the black polymorph is obtained. Heating in polysulfide solutions convert it into the red polymorph.<ref>[https://illumina-chemie.de/viewtopic.php?f=69&t=3336 https://illumina-chemie.de/viewtopic.php?f=69&t=3336]</ref> | ||
Latest revision as of 21:34, 10 July 2022
| Names | |
|---|---|
| IUPAC name
Mercury sulfide
| |
| Other names
Cinnabar
Mercuric sulfide Mercury sulphide Mercury(II) sulfide Vermilion | |
| Properties | |
| HgS | |
| Molar mass | 232.66 g/mol |
| Appearance | Red solid (α-HgS) Black solid (β-HgS) |
| Odor | Odorless |
| Density | 8.10 g/cm3 |
| Melting point | 580 °C (1,076 °F; 853 K) (decomposes) |
| Boiling point | Decomposes |
| Insoluble | |
| Solubility | Insoluble in organic solvents |
| Vapor pressure | ~0 mmHg |
| Thermochemistry | |
| Std molar
entropy (S |
78 J·mol−1·K−1 |
| Std enthalpy of
formation (ΔfH |
−58 kJ·mol−1 |
| Hazards | |
| Safety data sheet | Sigma-Aldrich |
| Related compounds | |
| Related compounds
|
Mercury(II) sulfate |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Mercury sulfide, also known as mercury(II) sulfide or mercuric sulfide is a chemical compound composed with the formula HgS. It occurs naturally as the mineral cinnabar .
Contents
Properties
Chemical
Mercury sulfide is resistant to the attack of most reagents, such as acids and bases.
It will however react with oxidizing mixtures at high temperatures, such as acidified dichromate solutions in conc. sulfuric acid, at temperatures above 100-150 °C.
However, mercury sulfide in cinnabar form will burn when ignited in air or a stream of pure oxygen, releasing sulfur dioxide and mercury vapors, which are very toxic and corrosive to many metals, like aluminium.[1]
- HgS + O2 → Hg + SO2
Physical
Mercury sulfide is a red or black solid, virtually insoluble in water and all solvents. The black form is the beta-polymorph (cubic structure) while the red form is the alpha-polymorph (hexagonal structure). The two forms can be interconverted, for example the red form is transformed into the red form by extended heating in a polysulfide solution.[2]
Availability
Cinnabar can be purchased from various mineral suppliers. In some countries its sale may be regulated.
Preparation
Mercury(II) sulfide can be created by adding elemental sulfur to mercury metal. Zinc powder is sometimes added to accelerate the reaction. Mercury sulfide is the main product of mercury disposal, as it is inert and safe to handle.
By precipitating mercury salts with hydrogen sulfide or soluble sulfides usually the black polymorph is obtained. Heating in polysulfide solutions convert it into the red polymorph.[3]
Projects
- Mineral collecting
- Make elemental mercury (VERY DANGEROUS)
Handling
Safety
Cinnabar is toxic and should be handled with proper protection.
Storage
In closed containers.
Disposal
Should be take to disposal centers.
References
- ↑ https://www.youtube.com/watch?v=2pMAfEPEHbI
- ↑ E. H. Pietsch et al., Gmelins Handbuch der anorganischen Chemie, Quecksilber Teil B Lieferung 3, 8th edition, 1968, Verlag Chemie GmbH, Weinheim/Bergstr., p. 954-967
- ↑ https://illumina-chemie.de/viewtopic.php?f=69&t=3336
