Arrhenius Base

Jul 2018
2
0
Pakistan
There are three sets of major theories by which acids and bases could be explained: Bronsted Lowry theory, Arrhenius theory and Lewis theory. In this article, we’ll see acids and bases based on the Arrhenius theory. Various compounds have similar characteristics which could be categorized into same groups and members of the same groups could be defined by their general behavior and characteristics. Even though it’s rational to define these chemical compounds in chemical terms; some general characteristics could explain their nature too. For instance, acids would taste sour but bases could taste bitter. Acids turn litmus paper red having a ph under 7 whereas bases turn litmus paper blue being on the ph scale over 7 and so on.

Arrhenius concept: Arrhenius bases and acids:
It was in the late 1800s when the Arrhenius theory, the definitions of acids and bases were introduced by Swedish Scientist Svante Arrhenius originally a physicist and also a chemist in physical science. He identified ions in water when compounds were added to it by observation of electrical conductivity; certain compounds are categorized as acids and bases based on the ions each compound releases after its addition in water.
 
Jan 2019
12
2
India
Arrhenius was one of the early exponents of electrolytic dissociation theory to define acids and bases. His classification of acids and bases was based on the theory that acids when dissolved in water, dissociate hydrogen ions and anions whereas bases when dissolved in water dissociate into hydroxyl ions and cations.
Thus HCl is acid and NaOH is a base and the neutralization process can be represented by a reaction involving the combination of H⁺ and OH⁻ ions to form H₂O.
HCl → H⁺ + Cl⁻
NaOH → Na⁺ + OH⁻
H⁺ + OH⁻ ⇆ H₂O

According to Bronsted Concept, a base is any molecules or ion, which accepts a proton. Lewis Concept recognizes that the base is an electron pair to donate, H⁺. So that during neutralization a coordinate bond is formed between the donor atom of the base and the proton.
H⁺ + :NH₃ ⇄ [H ← :NH₃]⁺
Thus all Bronsted bases are bases in Lewis sense also.

According to Arrhenius, an acid when dissolved in water dissociate into hydrogen ions and anions, that is it releases hydrogen ions (H+). Since the proton can receive electron pair from a base. Thus all the Arrhenius acids are also acids under the Lewis definition.