Cadmium sulfate

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Cadmium sulfate
Cadmium sulfate
Names
IUPAC name
Cadmium(II) sulfate
Other names
Sulfuric acid, cadmium salt (1:1),
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.030.288
EC Number 233-331-6
8295
RTECS number EV2700000
UNII
UN number 2570
Properties
CdSO4
CdSO4·H2O (monohydrate)
3CdSO4·8H2O (octahydrate)
Molar mass 208.47 g/mol (anhydrous)
226.490 g/mol (monohydrate)
769.546 g/mol (octahydrate)
Appearance White hygroscopic solid
Odor odorless
Density 4.691 g/cm3 (anhydrous)
3.79 g/cm3 (monohydrate)
3.08 g/cm3 (octahydrate)[1]
Melting point 1,000 °C (1,830 °F; 1,270 K) (anhydrous)
105 °C (monohydrate)
40 °C (octahydrate)
Boiling point (decomposes to basic sulfate and then oxide)
anhydrous:
75 g/100 mL (0 °C)
76.4 g/100 mL (25 °C)
58.4 g/100 mL (99 °C)
monohydrate:
76.7 g/100 mL (25 °C)
octahydrate:
very soluble
Solubility slightly soluble in methanol, ethyl acetate
insoluble in ethanol
-59.2·10−6 cm3/mol
1.565
Structure
orthorhombic (anhydrous)
monoclinic (hepta & octahydrate)
Thermochemistry
123 J·mol−1·K−1[2]
−935 kJ·mol−1[2]
Hazards
Safety data sheet [1]
GHS pictograms The skull-and-crossbones pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)The health hazard pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)The environment pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)
GHS signal word Danger
H301, H330, H340, H350, H360, H372, H400, H410
P201, P202, P260, P264, P270, P271, P273, P281, P284, P301+310, P304+340, P308+313, P310, P314, P320, P321, P330, P391, P403+233, P405, P501
NFPA 704
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g., canola oilHealth code 3: Short exposure could cause serious temporary or residual injury. E.g., chlorine gasReactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogenSpecial hazards (white): no codeNFPA 704 four-colored diamond
1
3
0
Lethal dose or concentration (LD, LC):
280 mg/kg (oral, rat)
US health exposure limits (NIOSH):
PEL (Permissible)
[1910.1027] TWA 0.005 mg/m3 (as Cd)[3]
REL (Recommended)
Ca[3]
IDLH (Immediate danger)
Ca [9 mg/m3 (as Cd)][3]
Related compounds
Other anions
Cadmium acetate,
Cadmium chloride,
Cadmium nitrate
Other cations
Zinc sulfate,
Calcium sulfate,
Magnesium sulfate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Cadmium sulfate is the name of a series of related inorganic compounds with the formula CdSO4·xH2O. The most common form is the monohydrate CdSO4·H2O, but two other forms are known CdSO4·​83H2O and the anhydrous salt (CdSO4). All salts are colourless and highly soluble in water.

Structure, preparation, and occurrence[edit]

X-ray crystallography shows that CdSO4·H2O is a typical coordination polymer. Each Cd2+ center has octahedral coordination geometry, being surrounded by four oxygen centers provided by four sulfate ligands and two oxygen centers from the bridging water ligands.[4]

Cadmium sulfate octohydrate can be prepared by the reaction of cadmium metal or its oxide or hydroxide with dilute sulfuric acid:

CdO + H2SO4 → CdSO4 + H2O
Cd + H2SO4 → CdSO4 + H2

The anhydrous material is prepared using sodium persulfate:

Cd + Na2S2O8 → CdSO4 + Na2SO4

Pure cadmium sulfate occurs as very rare minerals drobecite (CdSO4·4H2O), voudourisite (monohydrate), and lazaridisite (the 8/3-hydrate).

Applications[edit]

Cadmium sulfate is used widely for the electroplating of cadmium in electronic circuits. It is also a precursor to cadmium-based pigment such as cadmium sulfide. It is also used for electrolyte in a Weston standard cell as well as a pigment in fluorescent screens.

References[edit]

  1. ^ Lide, David R., ed. (2006). CRC Handbook of Chemistry and Physics (87th ed.). Boca Raton, FL: CRC Press. ISBN 0-8493-0487-3. 
  2. ^ a b Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A21. ISBN 0-618-94690-X. 
  3. ^ a b c "NIOSH Pocket Guide to Chemical Hazards #0087". National Institute for Occupational Safety and Health (NIOSH). 
  4. ^ Theppitak, C/; Chainok, K. "Crystal structure of CdSO4(H2O): A Redetermination" Acta Crystallographica, Section E. Structure Reports Online 2015, volume 71, pi8-pi9. Template:Doii