Mercury(II) sulfate

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Mercury(II) sulfate
Kwik(II)sulfaat t.png
Identifiers
CAS number 7783-35-9 YesY
PubChem 24544
Properties
Molecular formula HgSO4
Molar mass 296.653 g/mol
Appearance white monoclinic crystals
Odor odorless
Density 6.47 g/cm³, solid
Sublimation conditions 450 °C Decomposes[2]
Solubility in water Decomposes in water to yellow mercuric subsulfate and sulfuric acid[3]
Solubility soluble in hot H2SO4, NaCl solution
insoluble in alcohol, acetone, ammonia
Structure
Crystal structure rhombic
Thermochemistry
Std enthalpy of
formation
ΔfHo298
-707.5 kJ mol-1[4]
Hazards
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 3: Short exposure could cause serious temporary or residual injury. E.g., chlorine gas Reactivity code 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g., calcium Special hazards (white): no codeNFPA 704 four-colored diamond
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Mercury(II) sulfate, commonly called mercuric sulfate, is the chemical compound HgSO4. 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[edit]

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[edit]

Mercury sulfate, HgSO4, can be produced two ways:

By heating concentrated H2SO4 with elemental mercury:[6]

Hg + 2 H2SO4 → HgSO4 + SO2 + 2 H2O

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

Uses[edit]

Denigés' reagent[edit]

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[edit]

As previously mentioned, HgSO4 was used as the catalyst for the production of acetaldehyde from acetylene and water.[9]

The use of HgSO4 as a catalyst in the production of Acetaldehyde

Oxymercuration-Demercuration of Alkenes[edit]

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[edit]

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]

Conversion of 2,5-dimethyhexyn-2,5-diol to 2,2,5,5-tetramethylte-trahydrofuran-3-one

Health Issues[edit]

Inhalation 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]

It has, however, been successfully used in the late 19th century to induce vomiting for medical reasons. [1]

References[edit]

  1. ^ a b "Chemicalbook". Retrieved 2 May 2011. 
  2. ^ 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. 
  3. ^ chembook
  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[edit]