Transition metal salts. Transition metal salts are often coloured. Centre: iron (III) chloride (FeCl3, in a reagent bottle). Clockwise, from bottom left: cobalt (II) chloride hexahydrate (CoCl2 6H2O, purple, in a vial), copper (II) sulphate pentahydrate (CuSO4 5H2O, blue, in a beaker), nickel (II) sulphate hexahydrate (NiSO4 6H2O, green-blue, in a beaker), potassium chromate (VI) (K2CrO4, yellow, in a vial), manganese (II) carbonate (MnCO3, pale pink, in a beaker), potassium dichromate (VI) solution (K2Cr2O7, orange, in a volumetric flask), potassium permanganate solution (KMnO4, purple, in an Erlenmeyer flask), ammonium metavanadate (V) solution (NH4VO3, yellow, in a flat-bottom boiling flask), chromium (III) potassium sulphate solution (KCr (SO4)2, dark blue, in a beaker). |