Chapter 18.1, Problem 9SSC

Interpretation Introduction

Interpretation:

The conjugate acid-base pairs in given reaction is to be identified.

Concept introduction:

The concept of conjugate acid-base pair is given by Bronsted-Lowry.

According to it,

Acid is a substance which donate hydrogen ion and Base is a substance which accept hydrogen ion.

When acid donates $H^{+}$, the species form is conjugate base and when base accepts $H^{+}$, the species form is conjugate acid.

Answer to Problem 9SSC

Conjugate acid: $H_3{O}^{+}$

Conjugate base: $N{O}_2{}^{-}$

Explanation of Solution

The equation is:

$HN{O}_2+H_{2}O\rightleftharpoons N{O}_2{}^{-}+H_3{O}^{+}$

Ammonium ion donates hydrogen ions to form $N{O}_2{}^{-}$. So it is conjugate base.

Water accepts proton to form $H_3{O}^{+}$ so it is conjugate acid.