Blue vitriol

Copper(II) sulfate

Structure of pentahydrate Crystals of CuSO4·5H2O
Names
IUPAC name Copper(II) sulfate
Other names Cupric sulfate Blue vitriol (pentahydrate) Bluestone (pentahydrate) Bonattite (trihydrate mineral) Boothite (heptahydrate mineral) Chalcanthite (pentahydrate mineral) Chalcocyanite (mineral)
Identifiers
CAS Number	7758-98-7 Y 7758-99-8 (pentahydrate) N 16448-28-5 (trihydrate) N 19086-18-1 (heptahydrate) N
3D model (Jmol)	Interactive image
ChEBI	CHEBI:23414 Y
ChEMBL	ChEMBL604 Y
ChemSpider	22870 Y
ECHA InfoCard	100.028.952
EC Number	231-847-6
E number	E519 (acidity regulators, ...)
KEGG	C18713 Y
PubChem	24462
RTECS number	GL8800000 (anhydrous) GL8900000 (pentahydrate)
UNII	KUW2Q3U1VV Y
InChI InChI=1S/Cu.H2O4S/c;1-5(2,3)4/h;(H2,1,2,3,4)/q+2;/p-2 Y Key: ARUVKPQLZAKDPS-UHFFFAOYSA-L Y InChI=1/Cu.H2O4S/c;1-5(2,3)4/h;(H2,1,2,3,4)/q+2;/p-2 Key: ARUVKPQLZAKDPS-NUQVWONBAI
SMILES [O-]S(=O)(=O)[O-].[Cu+2]
Properties
Chemical formula	CuSO4 (anhydrous) CuSO4·5H2O (pentahydrate)
Molar mass	159.609 g/mol (anhydrous) 249.685 g/mol (pentahydrate)
Appearance	gray-white (anhydrous) blue (pentahydrate)
Density	3.60 g/cm3 (anhydrous) 2.286 g/cm3 (pentahydrate)
Melting point	110 °C (230 °F; 383 K) decomposes (·5H2O) <560 °C decomposes
Solubility in water	1.055 molal (10 °C) 1.26 molal (20 °C) 1.502 molal (30 °C)
Solubility	anhydrous insoluble in ethanol pentahydrate soluble in methanol 10.4 g/L (18 °C) insoluble in ethanol
Magnetic susceptibility (χ)	+1330·10−6 cm3/mol
Refractive index (nD)	1.724–1.739 (anhydrous) 1.514–1.544 (pentahydrate)
Structure
Crystal structure	Orthorhombic (anhydrous, chalcocyanite), space group Pnma, oP24, a = 0.839 nm, b = 0.669 nm, c = 0.483 nm. Triclinic (pentahydrate), space group P1, aP22, a = 0.5986 nm, b = 0.6141 nm, c = 1.0736 nm, α = 77.333°, β = 82.267°, γ = 72.567°
Thermochemistry
Std molar entropy (So298)	5 J K−1 mol−1
Std enthalpy of formation (ΔfHo298)	−769.98 kJ/mol
Pharmacology
ATC code	V03AB20 (WHO)
Hazards
Safety data sheet	anhydrous pentahydrate
GHS pictograms
EU classification (DSD)	Harmful (Xn) Irritant (Xi) Dangerous for the environment (N)
R-phrases	R22, R36/38, R50/53
S-phrases	(S2), S22, S60, S61
NFPA 704	0 2 1
Flash point	Non-flammable
Lethal dose or concentration (LD, LC):
LD50 (median dose)	300 mg/kg (oral, rat)
US health exposure limits (NIOSH):
PEL (Permissible)	TWA 1 mg/m3 (as Cu)
REL (Recommended)	TWA 1 mg/m3 (as Cu)
IDLH (Immediate danger)	TWA 100 mg/m3 (as Cu)
Related compounds
Other cations	Iron(II) sulfate Manganese(II) sulfate Nickel(II) sulfate Zinc sulfate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Copper(II) sulfate, also known as cupric sulfate, or copper sulphate, is the inorganic compound with the chemical formula CuSO₄(H₂O)_x, where x can range from 0 to 5. The pentahydrate (x = 5) is the most common form. Older names for this compound include blue vitriol, bluestone,vitriol of copper, and Roman vitriol.

The pentahydrate (CuSO₄·5H₂O), the most commonly encountered salt, is bright blue. It exothermically dissolves in water to give the aquo complex [Cu(H₂O)₆]²⁺, which has octahedral molecular geometry. The structure of the solid pentahydrate reveals a polymeric structure wherein copper is again octahedral but bound to four water ligands. The Cu(II)(H₂O)₄ centers are interconnected by sulfate anions to form chains.Anhydrous copper sulfate is a white powder.

Copper sulfate is produced industrially by treating copper metal with hot concentrated sulfuric acid or its oxides with dilute sulfuric acid. For laboratory use, copper sulfate is usually purchased. Copper sulfate can also be produced by slowly leaching low grade copper ore in air; bacteria may be used to hasten the process.

Commercial copper sulfate is usually about 98% pure copper sulfate, and may contain traces of water. Anhydrous Copper sulfate is 39.81 percent copper and 60.19 percent sulfate by mass, and in its blue, hydrous form, it is 25.47% copper, 38.47% sulfate (12.82% sulfur) and 36.06% water by mass. Four types of crystal size are provided based on its usage: large crystals (10–40 mm), small crystals (2–10 mm), snow crystals (less than 2 mm), and windswept powder (less than 0.15 mm).

Copper(II) sulfate pentahydrate decomposes before melting. It loses two water molecules upon heating at 63 °C (145 °F), followed by two more at 109 °C (228 °F) and the final water molecule at 200 °C (392 °F). Dehydration proceeds by decomposition of the tetraaquacopper(2+) moiety, two opposing aqua groups are lost to give a diaquacopper(2+) moiety. The second dehydration step occurs with the final two aqua groups are lost. Complete dehydration occurs when the only unbound water molecule is lost. At 650 °C (1,202 °F), copper(II) sulfate decomposes into copper(II) oxide (CuO) and sulfur trioxide (SO₃).