Title: Aluminum Potassium Sulfate
CAS Registry Number: 10043-67-1
Molecular Formula: AlKO8S2
Molecular Weight: 258.21
Percent Composition: Al 10.45%, K 15.14%, O 49.57%, S 24.84%
Line Formula: KAl(SO4)2
Literature References: Prepn: Gmelins, Aluminum (8th ed.) 35B, 453-477 (1934). Crystal structure: Manoli et al., Bull. Soc. Chim. Fr. 1970, 98; of dodecahydrate: Larson, Cromer, Acta Crystallogr. 22, 793 (1967).
Derivative Type: Anhydrous
Additional Names: Burnt alum; exsiccated alum
Properties: Usually about 97-98% pure. White powder; styptic taste; attracts moisture from the air. One gram dissolves in about 20 ml cold or 1 ml boiling water, usually incompletely; practically insol in alcohol. Keep well closed.
Derivative Type: Dodecahydrate
Additional Names: Alum; potassium alum; kalinite
Properties: The technical product is also known as alum flour, alum meal, cube alum. It is about 99.5% pure. Colorless, odorless, hard, large, transparent crystals or cryst fragments or white, cryst powder; sweetish, astringent taste. Stable at ordinary temp; when kept for a long time at 60-65° (or over H2SO4) loses 9 H2O which is reabsorbed on exposure to air. Becomes anhydr at about 200°; at higher temp loses SO3 and becomes basic and incompletely sol in water. d 1.725. mp 92.5°. One gram dissolves in 7.2 ml water, in 0.3 ml boiling water; freely sol in glycerol. Insol in alcohol. The aq soln is acid; pH of 0.2 molar aq soln 3.3.
Melting point: mp 92.5°
Density: d 1.725
Use: In dyeing, printing fabrics; manuf dyes, lakes, paper, vegetable glue, marble cement, porcelain cement, explosives; in tanning, hardening gelatin, baking powders, purifying water, clarifying sugar, hardening plaster casts; electrolytic copperplating; as catalyst in synthesis of ammonia; as mordant in staining with carmine, eosine, hematoxylin; clarifier (as alumina cream); identifying coloring matters; hardening agent in microscopy.
Therap-Cat: Astringent.
Therap-Cat-Vet: Astringent.
Keywords: Astringent. |