Mercury(II) sulfate sample and original bottle.
| IUPAC name
| Other names
|Molar mass||296.653 g/mol|
|Appearance||White crystalline powder|
|Melting point||450 °C (842 °F; 723 K) (decomposes)|
|Boiling point||Sublimes; decomposes|
|Decomposes to sulfuric acid and HgSO4·2HgO|
|Solubility|| Soluble in conc. hydrochloric acid, nitric acid, dil. sulfuric acid, aq. NaCl solution|
Insoluble in acetone, ammonia, ethanol, halocarbons, hydrocarbons
|Vapor pressure||~0 mmHg|
Std enthalpy of
|Safety data sheet||Fischer Scientific|
| Zinc sulfate|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Mercury(II) sulfate or mercuric sulfate, is the chemical compound HgSO4, a toxic and corrosive compound of mercury, used in various chemical reactions, though mostly used in analytical chemistry.
Mercury(II) sulfate readily hydrolyzes in water, separating into the yellow mercuric subsulfate and sulfuric acid:
- 3 HgSO4 + 2 H2O → HgSO4·2HgO + 2 H2SO4
Heating mercury(II) sulfate above 450 °C will cause it to decompose, releasing hazardous mercury vapors:
- HgSO4 → Hg + SO2 + O2
Mercury(II) sulfate is a dense white solid, soluble in concentrated mineral acids, such as nitric acid, sulfuric acid, but insoluble in organic solvents. It hydrolyzes in contact with water, forming yellow mercuric subsulfate and sulfuric acid. Mercury sulfate decomposes when heated to 450 °C. Its density at standard conditions is 6.47 g/cm3.
Mercury(II) sulfate is sold by chemical suppliers. Due to its hazards, this compound is extremely difficult to acquire by the amateur chemist. In the EU, purchasing mercury compounds requires a hazard permit.
- Hg + 2 H2SO4 → HgSO4 + SO2 + 2 H2O
It can also be made by reacting mercuric oxide with concentrated sulfuric acid.
- HgO + H2SO4 → HgSO4 + H2O
Concentrated acid needs to be used, to prevent hydrolysis.
- Detect tertiary alcohols
- Acetaldehyde synthesis from acetylene and water
- Phthalic anhydride synthesis
- Removal of chloride ions in COD analysis
HgSO4 is extremely toxic and its ingestion may be fatal. Exposure to mercury compounds will cause severe neurological damage. Reaction with water releases sulfuric acid, which is corrosive. The salt itself or as a solution is corrosive to many metals, such as aluminium, copper, iron (most steels), lead, magnesium, zinc, etc.
Mercury(II) sulfate should be stored in closed bottles, away from moisture, in a special cabinet for hazardous substances.
Best to take it to hazardous waste disposal centers.