Difference Between Alkali and Alkaline

Alkali vs Alkaline

Generally, alkali is used to indicate bases. It is used as a noun and alkaline is used as an adjective. However, in this context, they are used to indicate group 1 and group 2 metals in the periodic table. However, when they are used to indicate elements, normally alkali metal and alkaline earth metal terms are used.


Alkali is a term commonly used for the metals in the group 1 of the periodic table. These are also known as alkali metals. Although H is also included in this group, it is somewhat different. Therefore, lithium (Li), sodium (Na), potassium (K), Rubidium (Rb), Cesium (Cs) and Francium (Fr) are members of this group. Alkali metals are soft, shiny, silvery color metals. They all have only one electron in their outer shell, and they like to remove this and form +1 cations. When the outer most electrons are excited, it comes back to the ground state while emitting radiation in the visible range. The emission of this electron is easy, thus alkali metals are very reactive. The reactivity increases down the column. They form ionic compounds with other electronegative atoms. More accurately, alkali is referred to the carbonate or the hydroxide of an alkali metal. They also have basic properties. They are bitter in taste, slippery, and react with acids to make them neutralized.


‘Alkaline’ has alkali properties. Group 1 and group 2 elements, which are also known as alkali metals and alkaline earth metals, are considered to be alkaline when they dissolve in water. Sodium hydroxide, potassium hydroxide, magnesium hydroxide, and calcium carbonate are some of the examples. Arrhenius defines the bases as the substances that produce OH- in solutions. Above molecules form OH- when dissolved in water, therefore, act like bases. Alkaline solutions react easily with acids producing water and salt molecules. They show a pH value higher than 7 and turn red litmus to blue. There are other bases except alkaline bases like NH3. They also have the same basic properties.

Alkaline can be used as an adjective to describe basic properties; also, alkaline can be used specifically to address group 2 elements, which are also known as alkaline earth metals. They contain Beryllium (Be) magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). They are soft and reactive elements. These elements have the ability to form +2 cations; therefore, make ionic salts with electronegative elements. When alkaline metals react with water, they form alkaline hydroxide (beryllium does not react with water).

What is the difference between Alkali and Alkaline?

• Alkali term is used to recognize group 1 elements, lithium (Li), sodium (Na), potassium (K), Rubidium (Rb), Cesium (Cs) and Francium (Fr). Alkaline term is used to represent group 2 elements Beryllium (Be) magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). Alkali metals are more reactive than the alkaline earth metals.

• Alkali metals are more soft in nature than the alkaline.

• Alkalis have one electron in the outer most shell and alkaline earth metals have two electrons.

• Alkali forms +1 cations, and alkaline forms +2 cations.