Blue vitriol is an archaic name for which chemical compound?
Copper (II) sulfate, also known as cupric sulfate or copper sulphate, is an inorganic compound with the chemical formula CuSO4.
This salt exists as a series of compounds that differ in their degree of hydration. The anhydrous form is a pale green or gray-white powder, whereas the pentahydrate (CuSO4·5H2O), the most commonly encountered salt, is bright blue. Copper (II) sulfate exothermically dissolves in water to give the aquo complex [Cu(H2O)6]2+, which has octahedral molecular geometry and is paramagnetic. Other names for copper(II) sulfate are "blue vitriol" and "bluestone".