Chemical Formula Al(OH)3
CAS No. 21645-51-2
Molecular weight of Al(OH)3 78.00 g/mol
Appearance White amorphous powder
Density of Aluminium Hydroxide 2.42 g/dm3
Flashpoint of Aluminium Hydroxide Non-Flammable
Melting Point of Aluminium Hydroxide 300 °C
Boiling Point of Aluminium Hydroxide 2980 °C
Water Solubility Insoluble
Solubility Practically insoluble in water. It dissolves in dilute mineral acids & in solution of alkali hydroxides.
Identification It gives reaction of Aluminium
Alkaline Impurities Any pink color disappears on the addition of 0.3 ml of 0.1 M Hydrochloric acid.
Neutralizing Capacity After 10 Min. – pH NLT 1.8
After 15 Min. – pH NLT 2.3
After 20 Min. – pH NLT 3.0
NMT 35 ml of 0.1 M NaOH is required
Chloride Not more than 1.0 %
Sulfate Not more than 1.0 %
Arsenic Not more than 4 ppm
Heavy metals Not more than 60 ppm
Assay Between 47.0 % to 60.0 % of Al2O3
Microbial contamination
TAMC Not more than 1000 CFU/gm
TYMC Not more than 100 CFU/gm


Water treatment