Alum, or aluminum sulfate, has many qualities, including:

 Alum, or aluminum sulfate, has many qualities, including: 

 

Appearance: Alum is a white, colorless, odorless, crystalline powder or granular mass. It can also be found in green, yellow, and red. 

Taste: Alum has an astringent and acid taste. 

Solubility: Alum is highly soluble in water. 

Melting and boiling points: Alum's melting point is 92.5° Celsius and its boiling point is around 200° Celsius. 

Density: Alum has a density of 1.725 g/cm3. 

Crystallization: Alum crystals usually crystallize in a regular octahedral form. 

Impurities: Alum is often contaminated with impurities in markets. 

Alum has many uses, including: 

Water treatment: Alum is used in water treatment plants to clarify drinking water. It can also be used in lakes to reduce phosphorus levels, which can help prevent algae blooms and other water quality issues. 

 

Medicine: Alum is used in medicine as an astringent and antiseptic. 

 

Cosmetics: Alum is used in cosmetics to tighten the skin and remove excess oil. 

Food: Alum is found

 in many food products.