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.
The disadvantages of the material are its relatively low nitrogen content, which increases storage and transportation costs, and its marked tendency to cause soil acidification, which is greater than that of any other nitrogen fertilizer material.

Chemical properties

White crystalline powder

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 which is readily soluble in water with a solubility of approximately 70 g in 100 g of water at 0°c. the ph of a 0.1 molar solution in water is approximately 5.5. it is used in caramel produc- tion and as a source of nitrogen for yeast fermentation. in bakery products, up to 0.25 part per 100 parts by weight of flour is used.

The Uses of Ammonium sulfate

May be used for the precipitation or fractionation of proteins or for purification of antibodies. Useful for crystallographic analysis of nucleic acids and proteins.

The Uses of Ammonium sulfate

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 solution, 3.2 M is for the precipitation of proteins from crude serum sources

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

Ammonium sulfate is a high-tonnage industrial chemical, but frequently may be considered a byproduct as well as intended end-product of manufacture. A significant commercial source of (NH4)2SO4 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. As a fertilizer, (NH4)2SO4 has the advantage of adding sulfur to the soil as well as nitrogen. By weight, the compound contains 21% N and 24% S. Ammonium sulfate also is used in electric dry cell batteries, as a soldering liquid, as a fire retardant for fabrics and other products, and as a source of certain ammonium chemicals.

General Description

White odorless solid. Sinks and dissolves in water.

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

Agricultural Uses

Ammonium sulphate, (NH₄)₂SO₄, a water-soluble crystalline salt is a nitrogenous fertilizer containing about 2 1 % nitrogen and 24 % sulphur. It occurs naturally as the mineral mascagnite and offers many advantages as a fertilizer, such as low hygroscopicity, good physical properties, excellent chemical stability, good agronomic effectiveness and long shelf life.
Ammoniacal nitrogen is fned in the soil in an exchangeable form until nitrated by nitrifying bacteria. The ammoniacal nitrogen of ammonium sulphate does not leach out easily. Ammonium sulphate is an acid forming fertilizer, and hence used in neutral or alkaline soils. In its free flowing form, it is directly applied to the soil or blended with other granular materials. Ammonium sulphate also supplies sulphur, which is an essential nutrient for plants.
Ammonium sulphate is a quick-acting fertilizer. It is resistant to leaching as it gets adsorbed on the soil colloids, clay and humus, and replaces calcium. This adsorbed ammonium salt is converted to nitrate by nitrifying bacteria for use by growing plants. Ammonium sulphate is produced in different ways, The major ones are: (i) Production from synthesized ammonia and sulphuric acid.
(ii) Production of ammonium sulphate fertilizer by the gypsum process is widely used in many developing countries. In this process, ammonia is used along with pulverized calcium sulphate, carbon dioxide and water. Here ammonia made from nitrogen and hydrogen, reacts with carbon dioxide gas to produce ammonium carbonate. Ground gypsum reacts with ammonium carbonate solution to form ammonium sulphate and calcium carbonate.
Ammonium sulphate is commonly transported in polythene or paper bags. It is adsorbed on soil colloids, clay and humus, replacing calcium. It is more beneficial than nitrate fertilizers at planting time. This adsorbed portion is slowly released and in about a month most of the ammonium sulphate is converted into the nitrate form, which is used by growing plants.
Since rice crops absorb nitrogen even in the ammoniacal form, ammonium sulphate fertilizer is used as a source of nitrogen for rice in the USA and Southeast Asia. In the USA, ammonium sulphate is also used for potato scab control.
The main disadvantages of ammonium sulphate are its acid forming nature, low nitrogen percentage (21%) and high costs for packaging, storage and transportation.

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.