We can find Acid, Bases and Salt in many areas in our life.
Acids are known to turn blue litmus paper into red and liberate dihydrogen on reacting with some metals.
Bases are known to turn red litmus paper blue, taste bitter and feel soapy.Example is washing soda used for washing purposes.
When acids and bases are mixed in the right proportion they react with each other to give salts Examples: sodium chloride, barium sulphate
Arrhenius Concept of Acids and Bases
Acids are $H^+$ donors while bases are OH donar. Eg, $H_2SO_4$ is acid, NaOH is base. Example Of Acid
The ionization of an acid HX (aq) can be represented by the following equations:
$HX (aq) -> H^+(aq) + X^– (aq)$
or
$HX(aq) + H_2O(l) -> H_3O^+(aq) + X^–(aq)$ Example Of Base
The ionization of an base is represented by the below equation
$MOH(aq) → M^+(aq) + OH^–(aq)$ Limitations of Arrhenius concept
It doesn’t give any information about basity of compounds like $NH_3$ not having OH groups.
The Bronsted-Lowry Acids and Bases
Acids are $H^+$ donars while bases are $H^+$ acceptors.
acids are proton donors and bases are proton acceptor
The acid-base pair that differs only by one proton is called a conjugate acid-base pair.
Eg:-
Lewis Acids and Bases
Lewis acids are $e^-$ pair acceptor while Lewis bases are $e^-$ pair donors.
Lewis acids are $e^-$ deficient compounds. Eg:- $Mg^{+2}$,$AlCl_3$,$BF_3$, $BCl_3$, etc.
Lewis bases are $e^-$ rich species. Eg:- $OH^-$, $Cl^-$, $NH_3$, $H_2O$
Comparison between Arrhenius,Bronsted-Lowry and Lewis
Examples
1.Conjugate acid and base of $HNO_2$ Answer
$H_2NO_2^+$ is the conjugate acid
$NO_2^-$ is the conjugate Base
2.Is $BCl_3$ a Lewis Acid or Lewis Base Answer
$BCl_3$ acts as a Lewis acid as it can accept a lone pair of electrons from species like ammonia or amine molecules.
