Potassium sulphate, also called sulphate of potash (SOP), arcanite, or archaically potash of sulfur, is the inorganic compound with formula K₂SO₄ is a white water-soluble solid.Potassium sulfate is a potassium salt.
Potassium sulfate K₂SO₄ a colorless compound having rhombic or hexagonal crystals. It readily forms double salts with the sulfate of trivalent metals, which are known as Alums. It also forms double salts with calcium, magnesium and sodium sulfates. It is widely employed as a fertilizer.