A copper salt made by the action of sulfuric acid on copper oxide; SYN. copper sulphate, cupric sulfate, cupric sulphate.
(II) CuSO4 substance usually found as a blue, crystalline, hydrated salt CuSO4.5H2O (also called blue vitriol). It is made from the action of dilute sulfuric acid on copper(II) oxide, hydroxide, or carbonate.
CuO + H2SO4 + 4H2O ® CuSO4.5H2O
When the hydrated salt is heated gently it loses its water of crystallization and the blue crystals turn to a white powder. The reverse reaction is used as a chemical test for water.
CuSO4.5H2O Ű CuSO4 + 5H2O