Cadmium sulfate

Cadmium sulfate
Cadmium sulfate
Cadmium sulfate
Names
IUPAC name
Cadmium(II) sulfate
Other names
Sulfuric acid, cadmium salt (1:1),
Identifiers
CAS Number
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.030.288
EC Number
  • 233-331-6
Gmelin Reference
8295
PubChem CID
RTECS number
  • EV2700000
UNII
UN number 2570
CompTox Dashboard (EPA)
InChI
  • InChI=1S/Cd.H2O4S/c;1-5(2,3)4/h;(H2,1,2,3,4)/q+2;/p-2 checkY
    Key: QCUOBSQYDGUHHT-UHFFFAOYSA-L checkY
  • InChI=1/Cd.H2O4S/c;1-5(2,3)4/h;(H2,1,2,3,4)/q+2;/p-2
    Key: QCUOBSQYDGUHHT-NUQVWONBAG
SMILES
  • [Cd+2].[O-]S([O-])(=O)=O
Properties
Chemical formula
  • 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 (221 °F; 378 K) (monohydrate, decomposes)
  • 40 °C (104 °F; 313 K) (octahydrate, decomposes)
Boiling point (decomposes to basic sulfate and then oxide)
Solubility in water
    • anhydrous:
    • 75 g/100 mL (0 °C (32 °F; 273 K))
    • 76.4 g/100 mL (25 °C (77 °F; 298 K))
    • 58.4 g/100 mL (99 °C (210 °F; 372 K))

    • monohydrate:
    • 76.7 g/100 mL (25 °C (77 °F; 298 K))

    • octahydrate:
    • very soluble
Solubility in methanol slightly soluble
Solubility in ethyl acetate slightly soluble
Magnetic susceptibility (χ)
−59.2×10−6 cm3/mol
Refractive index (nD)
1.565
Viscosity
  • 2.41 mPa·s (20 °C (68 °F; 293 K))
  • 1.49 mPa·s (40 °C (104 °F; 313 K))
Structure
Crystal structure
  • orthorhombic (anhydrous)
  • monoclinic (mono & octahydrate)
Thermochemistry
Std molar
entropy (S298)
123 J⋅mol−1·K-1[2]
Std enthalpy of
formation fH298)
−935 kJ⋅mol−1[2]
Hazards[4]
GHS labelling:
Pictograms
GHS06: ToxicGHS08: Health hazardGHS09: Environmental hazard
Signal word
Danger
Hazard statements
H301, H330, H340, H350, H360, H372, H410
Precautionary statements
P201, P202, P260, P264, P270, P271, P273, P280, P284, P301+P310+P330, P304+P340+P310, P308+P313, P403+P233, P405, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamond
3
1
1
Threshold limit value (TLV)
  • 0.01 mg/m3 (total dust)
  • 0.002 mg/m3 (respirable dust)
(TWA)
Lethal dose or concentration (LD, LC):
LD50 (median dose)
107 mg/kg (oral, rat, analgous compound)
LC50 (median concentration)
0.75 mg/L (goldfish, analgous compound)
NIOSH (US health exposure limits):[5]
PEL (Permissible)
TWA 0.005 mg/m3 (as Cd)
REL (Recommended)
TWA 0.005 mg/m3 (as Cd)
IDLH (Immediate danger)
9 mg/m3 (as Cd)
Safety data sheet (SDS)
  • Fisher Scientific[3]
  • Sigma-Aldrich[4]
Related compounds
Other anions
Other cations
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: the octahydrate (3CdSO4·8H2O) and the anhydrous salt (CdSO4). All salts are colourless and highly soluble in water.

Preparation

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 can be prepared using sodium persulfate:

Cd + Na2S2O8 → CdSO4 + Na2SO4

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.

Structure

Portion of structure of CdSO4 illustrating the distorted tetrahedral geometry at Cd (dark blue spheres).[6]

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.[7]

Occurrence

Cadmium sulfates occur as the following rare minerals drobecite (CdSO4·4H2O), voudourisite (monohydrate), and lazaridisite (the octahydrate).

Safety

Cadmium sulfate (along with cadmium and its compounds) are classified as group 1 (human carcinogens) by IARC and have been identified as causing lung and prostate cancer as well as mutagenic effects in humans.[8]

References

  1. ^ Lide, David R., ed. (2006). CRC Handbook of Chemistry and Physics (87th ed.). Boca Raton, Florida: CRC Press. ISBN 0-8493-0487-3.
  2. ^ a b Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A21. ISBN 978-0-618-94690-7.
  3. ^ a b "Safety Data Sheet - Cadmium Sulfate". fishersci.com. ThermoFisher Scientific. 28 December 2021. p. 3. Retrieved 21 October 2025.
  4. ^ a b "Safety Data Sheet - Cadmium Sulfate". sigmaaldrich.com. Sigma-Aldrich. 20 May 2025. Retrieved 21 October 2025.
  5. ^ "NIOSH Pocket Guide to Chemical Hazards".
  6. ^ 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. Bibcode:1980ZK....153..121A. doi:10.1524/zkri.1980.0011.
  7. ^ Theppitak, C.; Chainok, K. (2015). "Crystal Structure of CdSO4(H2O): A Redetermination". Acta Crystallographica Section E. 71 (10): i8–pi9. doi:10.1107/S2056989015016904. PMC 4647421. PMID 26594423.
  8. ^ "Cadmium". Beryllium, Cadmium, Mercury, and Exposures in the Glass Manufacturing Industry (PDF). Lyon, France: World Health Organization - International Agency for Research on Cancer. February 1993. p. 210. ISBN 92-832-1258-4. ISSN 0250-9555. Retrieved 21 October 2025.