Characteristic

 

Potassium sulfate (in British English potassium sulphate (SOP), also called sulphate of potash, arcanite, or archaically known as potash of sulfur) is the inorganic compound with formula K₂SO₄. It is a white water-soluble solid. 

Chemical formula:K₂SO₄

Molar mass:174.259 g/mol

Appearance:White solid

Odor:odorless

Density:2.66 g/cm³

Melting point:1,069 °C (1,956 °F; 1,342 K)

Boiling point:1,689 °C (3,072 °F; 1,962 K)

Solubility in water:111 g/L (20 °C);120 g/L (25 °C);240 g/L (100 °C)

Solubility:slightly soluble in glycerol;insoluble in acetone, alcohol, CS2

Magnetic susceptibility (χ):−67.0·10⁻⁶ cm³/mol

Refractive index (nD):1.495

Crystal structure:orthorhombic

 

Application

 

Potassium sulfate is used in the production of fertilizers (i.e. providing potassium and sulfur), potassium alum, potassium carbonate and glass. In analytical chemistry, it is used in the determination of nitrogen by the Kjeldahl method and protein in foodstuffs. Also, it is used in the electrostatic effects on pKa values of amino acid residues in the staphylococcal nuclease. It is used in the separation of protein through electrophoresis and also serves as a laboratory reagent.