Question

Assertion:
A substance that can either act as an acid or a base is called ampholyte.
Reason:
Bisulfite ion ( $H{{S}^{-}}$ ) and bicarbonate ion ( $HC{{O}_{3}}^{-}$) are ampholytes.
(A) Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
(B) Both Assertion and Reason are correct and Reason is not the correct explanation for Assertion
(C) Assertion is correct but Reason is incorrect
(D) Assertion is incorrect but Reason is correct

Answer 1

Hint: According to Arrhenius theory of acid and bases, classifies a substance an acid if it produces hydrogen ions ${{H}^{+}}$ or hydronium ions in water. Similarly, a substance is classified as a base if it produces hydroxide ions $O{{H}^{-}}$ in water. This Arrhenius theory of acid and bases also explained several phenomena like neutralization, salt hydrolysis, the strength of acids and bases, etc.

Complete step by step answer:
An amphoteric species is a molecule or ions which can react as an acid as well as the base. These Amphoteric substances are called ampholytes, which are undergoing hydrolysis as well as ionization.
Hence, given the assertion statement is true.
Given bicarbonate ion $HC{{O}_{3}}^{-}$ which acts as an acid as well as a base.
${{H}_{2}}C{{O}_{3}}\rightleftharpoons {{H}^{+}}+HC{{O}_{3}}^{-}$

In the above equation, $HC{{O}_{3}}^{-}$ acts as a conjugate base
$C{{O}_{3}}^{2-}+{{H}^{+}}\rightleftharpoons HC{{O}_{3}}^{-}$

In the above equation, the bicarbonate ion acts as a conjugate acid.
Hence, bicarbonate ions is an ampholyte.
Given bisulfite ion $H{{S}^{-}}$ , which is act as an acid as well as base as follows,
$H{{S}^{-}}+{{H}_{2}}O\rightleftharpoons {{S}^{2-}}+{{H}_{3}}{{O}^{+}}$
$H{{S}^{-}}+{{H}_{3}}{{O}^{+}}\rightleftharpoons {{H}_{2}}S+{{H}_{2}}O$

Hence, Bisulfite ion ( $H{{S}^{-}}$ ) and bicarbonate ion ( $HC{{O}_{3}}^{-}$) are ampholytes.
So, Both Assertion and Reason are correct and Reason is not the correct explanation for Assertion
So, the correct answer is “Option B”.

Note: The limitations of the Arrhenius concept are the presence of water is necessary for the acidic or basic properties of substances. The acidic and basic characteristics of substances in non-aqueous solvents are not explained by this concept. The acidic character of certain salts in aqueous solution was not explained by this concept.