Ammonium sulfate, (NH₄)₂SO₄, sometimes commonly know as Mohrs Salt, is a colorless-to-gray, rhombohedral crystalline substance that occurs in nature as the mineral mascagnite. It is soluble in water and insoluble in alcohol or liquid ammonia. It is prepared commercially by passing ammonia, obtained from destructive distillation of coal, into sulfuric acid and is used as a fertilizer, in preparing other ammonium compounds, and for fireproofing.

Properties of Ammonium Sulfate

Appearance: Fine white granules or crystals.

Odor: Slight odor of ammonia.

Solubility: Appreciable in water. 41.22 g/100 g water @ 25C (77F)

Density: 1.77 @ 50C(122F)

pH: 5.5 (0.1M aqueous solution)

% Volatiles by volume @ 21C (70F): 0

Boiling Point: Not applicable.

Melting Point: 235 - 280C (455 - 536F) Decomposes.