Cadmium sulfate

Cadmium sulfate

Names
IUPAC name Cadmium(II) sulfate
Other names Sulfuric acid, cadmium salt (1:1), Niedermayrite
Identifiers
CAS Number	10124-36-4 Y 7709-84-3 (monohydrate) N 15244-35-9 (octahydrate) N
3D model (Jmol)	Interactive image
ChEBI	CHEBI:50292 Y
ChemSpider	23335 Y
ECHA InfoCard	100.030.288
EC Number	233-331-6
RTECS number	EV2700000
UNII	947UNF3Z6O Y
UN number	2570
InChI InChI=1S/Cd.H2O4S/c;1-5(2,3)4/h;(H2,1,2,3,4)/q+2;/p-2 Y Key: QCUOBSQYDGUHHT-UHFFFAOYSA-L Y 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 (monohydrate) 40 °C (octahydrate)
Boiling point	(decomposes to basic sulfate and then oxide)
Solubility in water	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
Refractive index (nD)	1.565
Structure
Crystal structure	orthorhombic (anhydrous) monoclinic (hepta & octahydrate)
Thermochemistry
Std molar entropy (So298)	123 J·mol−1·K−1[2]
Std enthalpy of formation (ΔfHo298)	−935 kJ·mol−1[2]
Hazards
Safety data sheet
EU classification (DSD)	Carc. Cat. 2 Muta. Cat. 2 Repr. Cat. 2 Very toxic (T+) Dangerous for the environment (N)
R-phrases	R45, R46, R60, R61, R25, R26, R48/23/25, R50/53
S-phrases	S53, S45, S60, S61
NFPA 704	1 3 0
Lethal dose or concentration (LD, LC):
LD50 (median dose)	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).
N verify (what is YN ?)
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 CdSO₄·8/3H₂O and the anhydrous salt (CdSO₄). All salts are colourless and highly soluble in water.

Preparation and occurrence

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

Cadmium sulfate is very rarely found naturally as the tetrahydrate mineral drobecite (CdSO₄·4H₂O) and as a basic salt in the mineral niedermayrite (Cu₄Cd(SO₄)₂(OH)₆·4H₂O).

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. 1 2 Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A21. ISBN 0-618-94690-X. 
3. 1 2 3 "NIOSH Pocket Guide to Chemical Hazards #0087". National Institute for Occupational Safety and Health (NIOSH).