Ammonium Aluminium Sulphate
Description
Ammonium Aluminium Sulphate, also known as ammonium alum, is a double salt of aluminium sulfate and ammonium sulfate, typically encountered as the dodecahydrate with the formula
(
N
H
4
)
A
l
(
S
O
4
)
2
⋅
12
H
2
O
(NH
4
)Al(SO
4
)
2
⋅12H
2
O.
Chemical and Physical Properties
Molecular formula:
(
N
H
4
)
A
l
(
S
O
4
)
2
⋅
12
H
2
O
(NH
4
)Al(SO
4
)
2
⋅12H
2
O.
Molar mass: 453.33 g/mol (dodecahydrate).
Appearance: Large, colorless crystals or white, odorless crystalline powder with astringent taste.
Solubility: Freely soluble in water, insoluble in alcohol.
Melting Point: 93.5 °C (dodecahydrate); decomposition occurs above ~250–280 °C.
Slightly acidic aqueous solution.
Major Uses and Applications
Water purification: Flocculant aiding in the removal of suspended impurities via formation of aluminium hydroxide precipitate.
Textile industry: Used in tanning, dyeing, and fireproofing textiles.
Cosmetics and deodorants: Used as an astringent and antiseptic; a common ingredient in crystal deodorants.
Baking and food: Used in baking powders and as a food additive (firming agent, acidity regulator).
Leather, paper, and pigment industries: Retanning leather, paper sizing, pigment stabilization.
Laboratory: Classical reagent for protein purification by precipitation and in niche analytical applications.
Safety and Handling
Irritant: Can cause irritation if inhaled, ingested, or on skin/eyes.
Emits toxic fumes (NOx, SOx) if decomposed by heat.
Store in a tightly closed container, protected from moisture due to hygroscopic nature.
Ammonium aluminium sulphate is a versatile, water-soluble inorganic salt with wide utility in water treatment, industry, and laboratory processes, prized for its effectiveness, affordability, and relatively low toxicity when handled properly.
Specifications
| Model No. | N-CH1187 |
|---|