硫酸亚铁铵（Ferrous ammonium sulfate）.docVIP

硫酸亚铁铵（Ferrous ammonium sulfate） Preparation of ammonium ferrous sulfate Experimental principle Iron is soluble in dilute sulfuric acid, ferrous sulfate: Fe+H2SO4=FeSO4+H2 = generation The interaction of ammonium sulfate and ferrous sulfate mass in aqueous solution, which generates lower solubility light green ammonium ferrous sulfate salt crystal: FeSO4+ (NH4) 2SO4+6H2O=FeSO4? 2SO4 (NH4) 6H2O down?. General ferrous salt in the air are easy to be oxidized, but the formation of salt but relatively stable, not easily oxidized. Experimental reagent 3mol/L sulfuric acid solution, 0.1mol/L sodium carbonate solution, iron filings (this experiment can also be iron powder), ammonium sulfate. Experimental instrument Electronic balance, a (10mL, 50mL), (50mL), beaker flask (250mL), pan (60mL), glass rod, iron, alcohol lamp, three tripod, asbestos net, dropper, spoon, suction bottle, Buchner funnel. Experimental procedures, experimental notes and experimental improvements I. purification of iron filings (1) a certain amount (m5.0g) of iron filings in a beaker; (2) add 40mL 0.1mol/LNa2CO3 solution, heating 5 ~ 10min; (3) pour out lye by pour out method; (4) water is used to rinse the iron filings with lye to prevent Na2SO4 crystals from mixing with FeSO4 after adding H2SO4; (5) pour out water by pour out method; (6) dry (faster drying) (1) if iron filings are used, the operations are as follows: if iron powder is used, it is recommended to omit the first step, because the purity of the iron powder is higher, and it is easy to be lost when it is turned out, and it is not easy to dry; (2) to shorten the reaction time, should try to increase the surface area of iron, iron shavings, the best selection of workshop of broken iron (silk), or a selection of fine spring curved scrap; waste wire screens are also available, but the purification and drying to cut into small pieces. (3) avoid the iron filings with too much corrosion. Because of the excessive surface Fe2O3, it can not be comp