Ammonium sulfate

Description

Ammonium sulfate was the first nitrogenous fertilizer made by the Haber-Bosch process, produced by the reaction of ammonia with sulfuric acid. In contrast with the nitrate salt, it is chemically stable, not highly hygroscopic. It also supplies supplemental sulfur to soils that may be deficient in this element, but this is of minor value when it is used on soils receiving applications of ordinary superphosphate.

Physical properties

White crystalline solid; orthorhombic crystal; density 1.769 g/cm³ at 20°C; melts between 511 to 515°C (in a closed system): however, in an open system, it melts with decomposition at 280°C; readily dissolves in water (solubility, 70.6 g and 104 g per 100 g water at 0°C and 100°C, respectively); insoluble in acetone, alcohol and ether.

Occurrence

Ammonium sulfate occurs in trace concentrations in the upper atmosphere. It is widely used as a fertilizer for rice and other crops. It is a source of sulfur for the soil. It is also used as an additive to supply nutrient nitrogen in fermentation processes (e.g., yeast production from molasses). It also is used for fireproofing timber and plastics, and in treatment of hides, and leather production.

The Uses of Ammonium sulfate

Ammonium Sulfate is a dough conditioner, firming agent, and pro- cessing aid. May be used for the precipitation or fractionation of proteins or for purification of antibodies. Useful for crystallographic analysis of nucleic acids and proteins. manufacture of ammonia alum; in the manufacture of H2SO4 to free it from nitrogen oxides; analytical uses; freezing mixtures, flameproofing fabrics and paper; manufacture of viscose silk; tanning, galvanizing iron; in fractionation of proteins. The commercial grade is used as fertilizer.

What are the applications of Application

Ammonium Sulfate is a reagent used in molecular biology and chromatography

Definition

ammonium sulphate: A whiterhombic solid, (NH₄)₂SO₄; r.d. 1.77;decomposes at 235°C. It is very solublein water and insoluble in ethanol.It occurs naturally as the mineralmascagnite. Ammonium sulphatewas formerly manufactured from the‘ammoniacal liquors’ produced duringcoal-gas manufacture but is nowproduced by the direct reaction betweenammonia gas and sulphuricacid. It is decomposed by heating torelease ammonia (and ammoniumhydrogensulphate) and eventuallywater, sulphur dioxide, and ammonia.Vast quantities of ammoniumsulphate are used as fertilizers.

Production Methods

A significant commercial source of Ammonium sulfate is its creation as a byproduct in the manufacture of caprolactam, which yields several tons of the compound per ton of caprolactam made. Ammonium sulfate also is a byproduct of coke oven operations where the excess NH3 formed is neutralized with H2SO4 to form (NH4)2SO4. In the Meresburg reaction, natural or byproduct gypsum is reacted with ammonium carbonate: CaSO4·2H2O + (NH4)2CO3 CaCO3 + (NH4)2SO4 +2 H2O The product is stable, free-flowing crystals.

Air & Water Reactions

Dissolves in water with evolution of some heat.

Reactivity Profile

Ammonium sulfate is acidic in aqueous solution. When a little Ammonium sulfate is added to fused potassium nitrite, a vigorous reaction occurs attended by flame [Mellor 2:702 1946-47].

Flammability and Explosibility

Not classified

Biochem/physiol Actions

Ammonium sulfate?((NH4)2SO4) is mainly used as a soil fertilizer. It is also used as a wood preservative. This inorganic salt plays a role in flame retardant chemicals.

Safety Profile

Moderately toxic by several routes. Human systemic effects by ingestion: hypermotility, diarrhea, nausea or vomiting. See also SULFATES. Incandescent reaction on heating with potassium chlorate. Reaction with sodmm hypochlorite gves the unstable explosive nitrogen trichloride. Incompatible with (K + NH4NO3), KNO2, (NaK + NH4NO3). When heated to decomposition it emits very toxic fumes of NOx, NH3, and SOx.

Purification Methods

Crystallise it twice from hot water containing 0.2% EDTA to remove metal ions, then finally from distilled water. Dry it in a desiccator for 2 weeks over Mg(ClO4)2. After 3 recrystallisations, ACS grade had Ti, K, Fe, Na at 11, 4.4, 4.4, 3.2 ppm respectively.