| Location | Main Location |
| Location Code | 204 Flammable 1 |
is a white inorganic compound with the chemical formula CuSO4. It is soluble in water and methanol, but insoluble in ethanol. When exposed to moisture, the compound absorbs water from the air, forming a hydrate called copper(II) sulfate pentahydrate, which has a blue color. The color change can be used as a test for the presence of water in a liquid.