Ferrous gluconate (iron (II) gluconate dihydrate, C12H22Fe14-2H2O) is a fine yellowish-gray or pale greenish-yellow powder or granules having a slight odor resembling that of burned sugar. It is prepared by reacting hot solutions or barium or calcium gluconate with ferrous sulfate or by heating freshly prepared ferrous carbonate with gluconic acid in aqueous solution. One g dissolves in about 10 mL of water with slight heating. It is practically insoluble in alcohol. A 1 in 20 solution is acid to litmus.
