1. Solubility In Water
Solubility: slightly soluble, about 0.8 g/l (20°C), forms a slightly acidic solution (pH ≈ 4).
Soluble products: Reacts with water to form metavanadate (HVO3) or, to a lesser extent, polyvanate (e.g., H2V4O11), depending on concentration and pH.
V2O5+H2O→2HVO3
Temperature effect: Solubility increases with increasing temperature (e.g., to about 5 g/L at 100°C).
2. Solubility In Acids
Strong acids (e.g. sulphuric, nitric, hydrochloric):
easily dissolves to form a vanadate cation (VO2+) or VO2+ (depending on acid concentration and reducing properties).
Example (in sulfuric acid):
V2O5+2H2SO4→2VO2++2SO42−+2H2O
Weak acids (e.g., acetic acid): Less soluble, requiring heating or high concentrations of acid.
3. Solubility In Alkalis
Strong alkalis (e.g. NaOH, KOH):
soluble, form colorless vanadates (e.g., sodium metavanadate NaVO3):
V2O5+2NaOH→2NaVO3+H2O
In concentrated alkalis, polyvadates (e.g., Na3VO4) can be formed.
