Ferric Sulphate Solution: Ferrous Sulphate Oxidised with Nitric Acid

The pharmacopoeia's solution of ferric sulphate, the starting point for iron salts such as ferric ammonium citrate. US Dispensatory (1907): ferrous sulphate is added to hot dilute sulphuric acid with nitric acid, which turns it into the red-brown ferric salt; the leftover nitric acid is boiled off and the whole made up to 1000 g. Hot strong acids and red fumes: outdoors, goggles and gloves. The picture: our own drawing.