Potassium aluminium sulphate, potassium alum, or potash alum is a chemical compound having the general formula KAl(SO4)2. Potash alum is a metal sulphate composed in the ratio of 1:1:2 using potassium, aluminium, and sulphate ions. The molecular weight of the chemical compound potash alum is 258.21 g/mol and the melting point is 92.5 °C, and the boiling point is 200 °C. This compound is insoluble in ethanol but freely soluble in water. It is hard, transparent crystals or crystalline fragments, colourless, large, white crystal powder. It is used in printing fabrics, dying, purifying water, etc.

How does the preparation of potash alum take place?

Alum is referred to as any group of hydrated double salts. It generally consists of water for hydration and aluminium sulphate. Alum sulphate can form alums with sulphate of single charged cations of caesium, sodium, potassium, and other compounds and elements. The most important alums known are ammonium aluminium sulphate, sodium aluminium sulphate, and potassium aluminium sulphate. Potash alum is also known as potassium aluminium sulphate or potassium alum which has a chemical formula  KAl(SO4)2. There is a common method of potash alum preparation by treating bauxite ore with sulphuric acid and potassium sulphate. In the making of potash alum, potassium sulphate and aluminium, sulphate is dissolved in water and then heated until the solution changes into pure crystals of potash alum. Alum can be produced easily from an aqueous solution by the method of precipitation. 

Uses of alum

There are several industrial and household uses of alum. The most often used alum is potassium alum; soda alum, ammonium alum, and ferric alum are also used for the same purposes.

1. Used in styptic pencil, which is used to stop bleeding caused by small cuts 
2. The adjuvant in vaccines( type of chemical which enhances the response of the immune)
3. As a chemical flocculant, it’s used in water purification
4. In deodorant, for example, rock
5. It is usually used at our homes in pickles as a pickling agent to ensure the crispiness of pickles.
6. For some types of baking soda, it’s used as the acidic component
7. Used as an ingredient in commercial and homemade modelling clay 
8. Used in flame retardant 
9. Used in hair removal creams and waxes
10. In some toothpaste
11. In some skin whiteners

Types of alum 

•  Potash alum: It is also called potassium alum or tawas or fitkari. It is aluminium potassium sulphate. It can be found easily in grocery stores for pickling and banking powder. Its chemical formula is KAl(SO4)2.
• Ammonium alum: The formula of ammonium alum is NH4Al(SO4)2·12H2O. Ammonium alum is mostly used for the common purposes of potassium alum and soda alum. Ammonium alum is used in dying, flame retardant in water purification, and some deodorant.
• The chemical formula for soda alum is NaAl(SO4)2·12H2O. It is used in food as an acidulant and baking powder.
• Chrome alum: chrome alum, also known as chromium alum, has the chemical formula of KCr(SO4)2·12H2O. The compound is deep violet and used for tanning, and it can be added to grow lavender and purple crystals in other alums.

Indication

Potassium alum is used in homoeopathic medicine and OTC products, and it’s considered safe by FDA. As it is used or found in different and many drugs, indications for the use of potassium alum are-

Helping the shrinkage of tissues. Oral health care drug, the dry of secretions. Cosmetic or drug astringent, skincare products, moisturisers, face powders, and deodorants, are part of the formulation in cleansing products. 

Side effects of alum

Several side effects are associated with alum. Some of them are given below:-

• Skin irritation 
• Dry skin 
• A feeling of Throat tightness 
• Fluid accumulation around the eye 
• Throat swelling
• Troubled breathing
• Puffy face from water retention
• Skin ulcer
• Life-threatening allergic reaction
• Hives( itchy and red skin)
• Hypersensitivity reaction

Conclusion

Potassium aluminium sulfate potassium alum or potash alum is a chemical compound having the general formula KAl(SO4)2. There is a common method of potash alum preparation by treating bauxite ore with sulphuric acid and that potassium sulfate. The molecular weight of the chemical compound potash alum is 258.21 and the melting point is 92.5 °C, and the boiling point is 200 °C. The most often used alum is potassium alum. There are soda alum, ammonium alum, and ferric alum, which are also used for the same purposes. Alum can be produced easily from an aqueous solution by the method of precipitation. Potassium alum is used in homoeopathic medicine and OTC products, and it’s considered safe by FDA. Ammonium alum is mostly used for common purposes as potassium alum and soda alum.