Question

Consider the reaction below. Which species are conjugate acid/base pairs? H2SO3 (aq) + CN (aq) HSO3 (aq)HCN (aq) A) HSO3, CN B) HSO3, H2SO3 C) H2SO 3, CN D) HCN, H2SO

Answer 1

Answer : The correct option is, (B) $H_2SO_3,HSO_3^-$

Explanation :

According to the Bronsted Lowry concept, Bronsted Lowry-acid is a substance that donates one or more hydrogen ion in a reaction and Bronsted Lowry-base is a substance that accepts one or more hydrogen ion in a reaction.

Or we can say that, conjugate acid is proton donor and conjugate base is proton acceptor.

The given equilibrium reaction is,

$H_2SO_3(aq)+CN^-\rightleftharpoons HSO_3^-(aq)+HCN(aq)$

Here, $H_2SO_3$ is loosing a proton, thus it is considered as an acid and after losing a proton, it forms $HSO_3^{-}$ which is a conjugate base. That means, $H_2SO_3/HSO_3^-$ are act as a conjugate acid-base pairs.

Hence, correct option is, (B) $H_2SO_3,HSO_3^-$