Question

What are acids and bases according to arrhenius theory?

Answer 1

According to Lord Arrhenius ,
All the compounds which in their aqueous forms dissociate H+ ions in water are acids and the one which dissociate OH- ions are the bases.

Answer 2

Arrhenius theory of acids and bases

The Swedish scientist Arrhenius put forth a theory of Acids and Bases in the year 1887. This theory gives definitions of acids and bases as follows :

Acid : An acid is a substance which on dissolving in water gives rise to H+ ion as the only cation.

HCl (g) water→(dissociation) H+(aq) + Cl-(aq)

H2SO4 (l) water→(dissociation) H+(aq) + SO4-(aq)

HSO4-(aq) (dissociation)→ H+(aq) + SO42-(aq)

Base : A base is a substance which on dissolving in water gives rise to the OH-ion as the only anion. For example, NaOH, Ca(OH)2.

NaOH (s) water→(dissociation) Na+(aq)+OH-(aq)

Ca(OH)2 (s) water→(dissociation) Ca2+(aq)+ 2OH-(aq)