Alkalis

As alkalis (from Latin sal alkali from arab.القلية / al-qalya  / ' potash '; Soda or sodium carbonate ) are substances that form alkaline solutions (lyes) with water . This not clearly defined group of substances includes, in particular, the oxides and hydroxides of the alkali and alkaline earth metals . Alkalis belong to the group of bases .

Alkalis are characterized by

1. their solubility in water
2. their corrosive, i.e. their aqueous solutions that have a destructive effect on plant and animal substances
3. their peculiar pungent taste
4. their ability to absorb carbon dioxide from the air , e.g. B. Soda lime
5. their ability to combine with acids to form salts
6. their property of forming soaps and glycerine with fats and fatty oils : saponification
7. Alkalis give reddish, damp litmus paper a bluish tinge .
8. Alkalis form hydroxide ions (OH ^- ) in solutions .