Iron Nitrates
Iron Nitrates
nitric acid salts of divalent and trivalent iron, Fe(NO3)2 and Fe(NO3)3, respectively. At normal temperature the crystal hydrates—the green Fe(NO3)2.6H2O, pale violet Fe(NO3)3–9H2O, and colorless Fe(NO3)3.6H2O—are stable. The salts are readily soluble in water; for example, 87.3 g of Fe(NO3)3.9H2O is dissolved in 100 g of water at 25°C. Fe(NO3)3 is used in technology as a mordant in dyeing cotton fabrics and for weighting silk. It is obtained by treating iron filings or bits of roofing iron with 20–30 percent solution of nitric acid. A more diluted solution of acid yields Fe(NO3)2.