Acids, bases & salts
Alkali — ক্ষার
Quick answer
A water-soluble base, such as , that releases OH⁻ ions; every alkali is a base, but not every base is an alkali.
Definition
An alkali is a base that dissolves in water to give hydroxide ions. Sodium hydroxide (), potassium hydroxide () and calcium hydroxide are common alkalis. Alkalis react with acids in neutralization to give a salt and water, turn red litmus blue and sit above pH 7. Watch the words: every alkali is a base, but only water-soluble bases earn the name alkali. The Group 1 elements are called alkali metals because they form alkalis with water.
For example
Sodium hydroxide solution cuts the grease on dirty dishes, and potassium hydroxide is used to make soft soap. Both are alkalis.