Vanadium(III) sulfate

Vanadium(III) sulfate is the inorganic compound with the formula V₂(SO₄)₃. It is a pale yellow solid that is stable to air, in contrast to most vanadium(III) compounds. It slowly dissolves in water to give the green aquo complex [V(H₂O)₆]³⁺.

Vanadium(III) sulfate^[1]

Names
IUPAC name Vanadium(III) sulfate
Other names Vanadium trisulfate Divanadium trisulfate
Identifiers
CAS Number	13701-70-7 Y
ChemSpider	19990317
ECHA InfoCard	100.033.827
EC Number	237-226-6
PubChem CID	166888
UNII	1EQF3LAK57 Y
CompTox Dashboard (EPA)	DTXSID90890715
Properties
Chemical formula	V2(SO4)3
Molar mass	390.074 g/mol
Appearance	Yellow powder
Melting point	400 °C (752 °F; 673 K) Decomposes
Solubility in water	Slightly soluble
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

The compound is prepared by treating V₂O₅ in sulfuric acid with elemental sulfur:^[2]

V₂O₅ + S + 3 H₂SO₄ → V₂(SO₄)₃ + SO₂ + 3 H₂O

This transformation is a rare example of a reduction by elemental sulfur.

When heated in vacuum at or slightly below 410 °C, it decomposes into vanadyl sulfate (VOSO₄) and SO₂. Vanadium(III) sulfate is stable in dry air but upon exposure to moist air for several weeks forms a green hydrate form.

Vanadium(III) sulfate is a reducing agent.