Mercury(II) sulfate

Mercury(II) sulfate
Other names Mercuric sulfate, Mercurypersulfate, Mercury Bisulfate[1]
Identifiers
CAS number	7783-35-9 Y
Properties
Molecular formula	HgSO4
Molar mass	296.65 g/mol
Appearance	white monoclinic crystals
Density	6.47 g/cm³, solid
Sublimation conditions	450 °C Decomposes[3]
Solubility in water	Decomposes in water to yellow mercuric subsulfate and sulfuric acid[2]
Solubility	soluble in hot H2SO4, NaCl solution
Thermochemistry
Std enthalpy of formation ΔfHo298	-707.5 kJ mol-1[4]
Hazards
NFPA 704	0 3 1
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Mercury(II) sulfate, commonly called mercuric sulfate is the chemical compound Hg S O₄. It is an odorless solid that forms white granules or crystalline powder. In water, it separates into an insoluble sulfate with a yellow color and sulfuric acid.^[4]

History

In 1932, the Japanese chemical company Chisso Corporation began using Mercury sulfate as the catalyst for the production of acetaldehyde from acetylene and water. Though it was unknown at the time, Methylmercury is formed as side product of this reaction. Exposure and consumption of the mercury waste products, including Methylmercury, that were dumped into Minamata Bay by Chisso are believed to be the cause of Minamata disease in Minamata, Japan^[5].

Production

Mercury Sulfate, HgSO₄, can be produced two ways:

By heating concentrated H₂SO₄ with elemental mercury^[6]

Or by dissolving solid yellow mercuric oxide in concentrated sulfuric acid and water. ^[7]

Uses

Denigés' reagent

An acidic solution of mercury sulfate is known as Denigés' reagent. It was commonly used throughout the 20th century as a qualitative analysis reagent. If Denigés' reagent is added to a solution containing compounds that have tertiary alcohols, a yellow or red precipitate will form.^[8]

Production of Acetaldehyde

As previously mentioned, Hg S O₄ was used as the catalyst for the production of acetaldehyde from acetylene and water.^[9]

Oxymercuration-Demercuration of Alkenes

Mercury Compounds such as mercury sulfate and mercury(II) acetate are commonly used as catalysts in the oxymercuration-demercuration, a type of Electrophilic Addition reactions. The hydration of an alkene results in an alcohol that follows regioselectivity that is predicted by Markovnikov's Rule^{[citation needed]}.

Hydration of Alkynes

The reaction scheme is provided below. The conversion of 2,5-dimethyhexyn-2,5-diol to 2,2,5,5-tetramethylte-trahydrofuran using aqueous mercury sulfate without the addition of acid.^[10]

Health Issues

Inhilation of HgSO₄ can result in acute poisoning: causing tightness in the chest, difficulties breathing, coughing and pain. Exposure of HgSO₄ to the eyes can cause ulceration of conjunctiva and cornea. If mercury sulfate is exposed to the skin it may cause sensitization dermatitis. Lastly, ingestion of mercury sulfate will cause necrosis, pain, vomiting, and severe purging. Ingestion can result in death within a few hours due to peripheral vascular collapse.^[1]

References

1. ^ ^{a b} "Chemicalbook". http://www.chemicalbook.com/ChemicalProductProperty_EN_CB8153036.htm. Retrieved 2 May 2011. 
2. ^ chembook
3. ^ Wu, Shengji; Uddin, Md. Azhar, Nagano, Saori, Ozaki, Masaki, Sasaoka, Eiji (2011). "Fundamental Study on Decomposition Characteristics of Mercury Compounds over Solid Powder by Temperature-Programmed Decomposition Desorption Mass Spectrometry". Energy & Fuels 25 (1): 144–153. doi:10.1021/ef1009499. 
4. ^ ^{a b} Lide, David R. (1998), Handbook of Chemistry and Physics (87 ed.), Boca Raton, FL: CRC Press, pp. 5–19, ISBN 0-8493-0594-2 
5. ^ http://www.hgtech.com/Information/Minamata_Japan.html
6. ^ http://www.epa.gov/hg/pdfs/mercury-rpt-to-congress.pdf
7. ^ Robey, R. F.; Robertson, N. C. (May 1947). "Test for tert-Butyl and Isopropyl Alcohols with Deniges Reagent". Analytical Chemistry 19 (5): 310–311. doi:10.1021/ac60005a007. 
8. ^ MARKS, E. M.; LIPKIN, D. (1939). "Reaction of Aliphatic Ethers with Denigés' Reagent". J. Org. Chem. 3 (6): 598–602. doi:10.1021/jo01223a008. 
9. ^ Vogt, R; Nieuwland, J (September 1921). "THE ROLE OF MERCURY SALTS IN THE CATALYTIC TRANSFORMATION OF ACETYLENE INTO ACETALYDEHYDE, AND A NEW COMMERCIAL PROCESS FOR THE MANUFACTURE OF PARALDEHYDE". J. Am. Chem. Soc. 43 (9): 2071–81. doi:10.1021/ja01442a010. 
10. ^ Wasacz, J. P.; Badding, V. G. (1982). "A hydration of an alkyne illustrating steam and vacuum distillation". Journal of Chemical Education 59 (8): 694. doi:10.1021/ed059p694. 

External links

• National Pollutant Inventory - Mercury and compounds Fact Sheet
• NIOSH Pocket Guide to Chemical Hazards