Chevreul's salt

Chevreul's salt
Names
	IUPAC name Copper(I, II) sulfite dihydrate
	Other names Chevreul's salt
Identifiers
CAS Number	13814-81–8 dihydrate; 15293-86-4 anhydrous ;
3D model (JSmol)	Interactive image;
ChemSpider	32699368 dihydrate; 154599 anhydrous;
PubChem CID	44148673 dihydrate; 177582 anhydrous;
UNII	D8UCX23711 dihydrate ; 4IVM1X62DM anhydrous ;
CompTox Dashboard (EPA)	DTXSID90929993 ;
	InChI InChI=1S/3Cu.2H2O3S.2H2O/c;;;21-4(2)3;;/h;;;2(H2,1,2,3);21H2/q2+1;+2;;;;/p-4 Key: IJBZIISYIRGDFM-UHFFFAOYSA-J;
	SMILES O.O.[O-]S(=O)[O-].[O-]S(=O)[O-].[Cu+].[Cu+].[Cu+2];
Properties
Chemical formula	Cu3H4O8S2
Molar mass	386.78 g·mol−1
Appearance	brick red powder
Density	3.57
Solubility	aqueous ammonia
Thermal conductivity	0.1 kWcm−1K−1
Structure
Crystal structure	monoclinic
Space group	P21/n
Lattice constant	a = 5.5671 Å, b = 7.7875 Å, c = c = 8.3635 Å α = 90°, β = 91.279o°, γ = 90°
Lattice volume (V)	362.5 Å3
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Chevreul's salt (copper(I,II) sulfite dihydrate, Cu₂SO₃•CuSO₃•2H₂O or Cu₃(SO₃)₂•2H₂O), is a copper salt which was prepared for the first time by a French chemist Michel Eugène Chevreul in 1812. Its unusual property is that it contains copper in both of its common oxidation states, making it a mixed-valence complex. It is insoluble in water and stable in air. What was known as Rogojski's salt is a mixture of Chevreul's salt and metallic copper.