Chemistry:Copper(I) sulfate

Short description: Chemical compound

Copper(I) sulfate

Names
Other names Copper(I) sulphate; Cuprous sulfate; Dicopper sulfate
Identifiers
CAS Number	17599-81-4
3D model (JSmol)	Interactive image
ChemSpider	118749
PubChem CID	134737
InChI InChI=1S/2Cu.H2O4S/c;;1-5(2,3)4/h;;(H2,1,2,3,4)/q2*+1;/p-2 Key: WIVXEZIMDUGYRW-UHFFFAOYSA-L InChI=1/2Cu.H2O4S/c;;1-5(2,3)4/h;;(H2,1,2,3,4)/q2*+1;/p-2 Key: WIVXEZIMDUGYRW-NUQVWONBAI
SMILES [O-]S(=O)(=O)[O-].[Cu+].[Cu+]
Properties
Chemical formula	Cu2SO4
Molar mass	223.15 g mol−1
Appearance	White
Density	4.12 g cm−3
Melting point	110 °C
Solubility in water	decomposes
Structure
Crystal structure	orthorhombic
Space group	Fddd
Lattice constant	a = 4.748(3) Å, b = 13.96(1) Å, c = 10.86(1) Å
Formula units (Z)	8
Hazards
NIOSH (US health exposure limits):
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)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Copper(I) sulfate, also known as cuprous sulfate, is the inorganic compound with the chemical formula Cu₂SO₄. It is a white solid that has attracted little attention, in contrast to copper(II) sulfate. It is an unusual example of a copper(I) compound derived from an oxyanion, illustrated also by the non- or fleeting existence of cuprous nitrate and cuprous perchlorate.

Structure

Cu₂SO₄ crystallizes in the orthorhombic space group Fddd. Each oxygen in a sulfate anion is bridged to another sulfate by a copper atom, and the Cu-O distances are 196 pm. The structure is intermediate between silver sulfate and solid sulfuric acid.

Synthesis

Cuprous sulfate is produced by the reaction of copper metal with sulfuric acid at 200 °C:

[math]\ce{ 2Cu + 2 H2SO4 -> Cu2SO4 + SO2 + 2 H2O }[/math]

The small amount of water produced in this reaction is absorbed by the sulfuric acid.

Cu₂SO₄ can also be synthesized by the action of dimethyl sulfate on cuprous oxide:

[math]\ce{ Cu2O + (CH3O)2SO2 -> Cu2SO4 + (CH3)2O }[/math]

The material is stable in dry air at room temperature but decomposes rapidly in presence of moisture or on heating. It disproportionates upon contact with water:

[math]\ce{ Cu2SO4 + 4 H2O -> Cu + [Cu(H2O)4]SO4 }[/math]

It can also be produced by the reaction of copper(II) sulfate and a reducing agent such as sodium thiosulfate.

Structure

Cu₂SO₄ crystallizes in the orthorhombic space group. The Cu-O distances are 196 pm.