Question

define alkalis and give example

Answer 1

Alkali salts are soluble hydroxides ofalkali metals and alkaline earth metals, of which common examples are: Sodium hydroxide – often called "caustic soda" Potassium hydroxide – commonly called "caustic potash"

Answer 2

Alkali:

Alkali term is used to describe the aqueous solution of a base. For example the ‘aqueous solution’ of sodium hydroxide is an alkali. Similarly, the aqueous solution of ‘potassium hydroxide’ is also an alkali that has hydroxyl ions in its solution.  

We can say that all basic compounds when mixed with water to form aqueous solution form alkali which have free hydroxyl ions in it.  

Examples:

The “hydroxides alkali metals” and “alkaline earth metals” are good examples alkalis.