* Dehydration: When you heat copper sulfate pentahydrate, the heat drives off the water molecules (H₂O) that are bound to the copper sulfate molecule. This is called dehydration.
* Color Change: The blue color of copper sulfate pentahydrate is due to the water molecules interacting with the copper ions (Cu²⁺). When the water is removed, the copper ions change their arrangement and no longer absorb light in the same way, resulting in a colorless or white appearance.
The reaction:
CuSO₄·5H₂O (blue) → CuSO₄ (white) + 5H₂O (g)
In summary: The blue color of copper sulfate pentahydrate is caused by the presence of water molecules. When these water molecules are driven off by heat, the compound becomes anhydrous (without water) and turns white.
