Copper Sulphate
Copper(II) sulphate, also known as copper sulphate, are the inorganic compounds with the chemical formula CuSO4(H2O)x, where x can range from 0 to 5. The pentahydrate (x = 5) is the most common form. Older names for this compound include blue vitriol, bluestone,[9] vitriol of copper, and Roman vitriol.
The pentahydrate (CuSO4·5H2O), the most commonly encountered salt, is bright blue. It exothermically dissolves in water to give the aquo complex [Cu(H2O)6]2+, which has octahedral molecular geometry. The structure of the solid pentahydrate reveals a polymeric structure wherein copper is again octahedral but bound to four water ligands. The Cu(II)(H2O)4 centers are interconnected by sulfate anions to form chains.[12] Anhydrous copper sulfate is a grey powder.
| Chemical formula | CuSO4 (anhydrous) , CuSO4·5H2O (pentahydrate) |
| Molar mass | 159.609 g/mol (anhydrous),249.685 g/mol (pentahydrate) |
| Appearance | gray-white (anhydrous),blue (pentahydrate) |
| Density | 3.60 g/cm3 (anhydrous),2.286 g/cm3 (pentahydrate) |
| Melting point | 110 °C (230 °F; 383 K) decomposes (·5H2O)[1] if pentahydrate <560 °C decomposes[1] if anhydrous |
| Boiling point | decomposes |
| Solubility in water | 1.055 molal (10 °C), 1.26 molal (20 °C), 1.502 molal (30 °C) |
| Solubility | anhydrous insoluble in ethanol |
| Magnetic susceptibility | +1330·10−6 cm3/mol |
| Refractive index | 1.724–1.739 (anhydrous), 1.514–1.544 (pentahydrate) |