Copper (II) sulfate

Copper (II) sulfate (CuSO₄) is the most common copper salt, made by the action of sulfuric acid on the base copper oxide. Copper (II) sulfate is a pale green powder.

Copper (II) sulfate is a desiccant, as such, it most commonly occurs as the hydrate CuSO₄ · 5H₂O. CuSO₄ · 5H₂O is a deep blue crystalline solid and dehydrates at 110°C. It decomposes at 600°C forming CuO and Cu₂O.

It can be used to plate metals with copper, as a fungicide or herbicide, or as a chemical test for water (the anhydrous form will absorb water, turning blue).

The archaic name for Copper (II) sulfate was Cupric sulfate. Some common names are: Blue Stone and Blue Vitriol.