Synthesis of alum (potassium alum)

Preparation of alum

Preparation of alum (potassium alum)

Preparation of alum (potassium alum)

25 g of aluminum sulfate are dissolved in 60 ml of boiling water. 7 g of potassium sulfate are dissolved with constant stirring and 1 g of 10% sulfuric acid is added. The hot solution is filtered and cooled to room temperature. During the cooling potassium alum crystallizes. The solution is filtered and mother-liquid is evaporated yielding additional crops of potassium alum crystals as far as practicable. Recrystallization once or twice yields pure potassium alum. Potassium alum forms large, colorless, octohedral crystals, sometimes modified by cubes, or occurs in crystalline fragments, without odor, but having a sweetish and strongly astringent taste.

Laboratory manual of inorganic and pharmaceutical preparations, by O. Miner, 9, 1911





InChI Key


Canonical SMILES


MeSH Synonyms

alum, aluminum hydrogen sulfate, aluminum potassium sulfate, aluminum sulfate, potassium aluminum sulfate

Depositor-Supplied Synonyms

Potassium alum, Potash alum, Alaun, Aluminum potassium sulfate, Potassium aluminum sulfate, Aluminum potassium disulfate, Burnt potassium alum, Aluminum potassium alum, Potassium aluminum alum, Alum potassium, Exsiccated alum, Burnt alum, ALUM, POTASSIUM, Aluminium potassium bis(sulphate), Tai-Ace K 20, Tai-Ace K 150, UNII-09OXB01F3O, Dialuminum dipotassium sulfate, CCRIS 6842, Aluminum potassium sulfate, alum, HSDB 2685, Sulfuric acid, aluminum potassium salt (2:1:1), EINECS 233-141-3, Aluminum potassium sulfate, anhydrous, Potassium aluminum sulfate (1:1:2), 10043-67-1, Aluminum potassium sulfate (AlK(SO4)2), Aluminum potassium sulfate (KAl(SO4)2), Alum, N.F, Alum, N.F., Alum, potassium anhydrous, potassium aluminum disulfate, AC1L2NQ3, AlK(SO4)2, 09OXB01F3O, CHEBI:86463, GRLPQNLYRHEGIJ-UHFFFAOYSA-J, 10043-01-3 (Parent), AKOS015856586, aluminium potassium sulfate (1/1/2), aluminium(3+) ion potassium disulfate, aluminium(3+) potassium ion disulfate, ALUMINUM POTASSIUM SULFATE, ACS, LS-7184, FT-0622226, FT-0626636, 131315-49-6

Share This

Leave a Reply

Your email address will not be published. Required fields are marked *