Types of Alkali and its Properties
Alkali is a chemical substance that changes the colour of wet red litmus paper to blue. Lime water is a strong alkali. Mineral substances such as calcium (lime), sodium, magnesium and aluminium act with other elements and dissolve in water to produce alkali. Alkali derives its name from an Arabic word al-qili which means “ashes of the saltwort plant” because hydroxide and carbonate of sodium and potassium leached from plant ashed. Alkaline substances are used in making soap, rayon and Sellotape, in processing paper pulp,in petroleum refining and in the manufacturing of many chemical products. Strong alkali is caustic. It can cause several burn to skin.
Alkali food substances taste bitter. Baking powder, ulam-ulam such as pegaga are example of alkaline food substances. Many household substances such as soup, detergent, shampoo, toothpaste and fabric softerner are alkaline substances.
Example of alkaline substances are Toothpastes, soaps and magnesia milk.