Acids and bases both have such properties that let them form ions in solutions. In any aqueous solution, bases produce hydroxide ions (OH-
) ions while acids produce hydrogen ions (H+
) .
This is because most of the bases and acids are ionic compounds, and acids contain hydrogen as positive while bases contain OH- (hydroxide) as negative ions.
If we talk about physical and chemical properties of acids, they are usually sour in taste and react with carbonates, active metals and bases.
If we talk about physical and chemical properties of bases, they are usually bitter in taste and react with acids.
Although different scientists differently define acids and bases but Arrhenius was the scientists who defined acids and bases based on their behavior in an aqueous solution. According to him, A base is a substance that produce hydroxide ion in a solution while acid is a substance that give H+ ion in an aqueous solution.
Let us take the examples of acids and bases:
Acid:
HCl (g) ---------------> H+ (aq) + Cl- (aq)
Base:
NaOH (s) --------------> Na+ (aq) + OH-
(aq)
Note: This is a generally accepted fact but there are exceptions as well like ammonia is basic in nature but it do not give hydroxide ion in aqueous solution.
Hope it helps!
