Chemistry:Cadmium sulfate

From HandWiki
Cadmium sulfate
Cadmium sulfate
Names
IUPAC name
Cadmium(II) sulfate
Other names
Sulfuric acid, cadmium salt (1:1),
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
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 GHS06: ToxicGHS08: Health hazardGHS09: Environmental hazard
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 (fire diamond)
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)
NIOSH (US health exposure limits):
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).
☒N verify (what is ☑Y☒N ?)
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

Portion of structure of CdSO4 illustrating the distorted tetrahedral geometry at Cd (dark blue spheres).[4]

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.[5]

Cadmium sulfate hydrate 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 caan prepared using sodium persulfate:

Cd + Na2S2O8 → CdSO4 + Na2SO4

Cadmium sulfates occur as the following rare minerals drobecite (CdSO4·4H2O), voudourisite (monohydrate), and lazaridisite (the 8/3-hydrate).

Applications

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

  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. 2.0 2.1 Zumdahl, Steven S. (2009). Chemical Principles 6th Ed.. Houghton Mifflin Company. p. A21. ISBN 978-0-618-94690-7. 
  3. 3.0 3.1 3.2 NIOSH Pocket Guide to Chemical Hazards. "#0087". National Institute for Occupational Safety and Health (NIOSH). https://www.cdc.gov/niosh/npg/npgd0087.html. 
  4. Aurivillius, Karin; Stålhandske, Claes (1980). "A Reinvestigation of the Crystal Structures of HgSO4 and CdSO4". Zeitschrift für Kristallographie - Crystalline Materials 153 (1–2): 121–129. doi:10.1524/zkri.1980.0011. Bibcode1980ZK....153..121A. 
  5. Theppitak, C.; Chainok, K. (2015). "Crystal Structure of CdSO4(H2O): A Redetermination"". Acta Crystallographica, Section E 71 (10): i8–pi9. doi:10.1107/S2056989015016904. PMID 26594423.