Chapter 8, Problem 8.21QP

(a)

Interpretation Introduction

Interpretation:

According to Arrhenius theory, an acid has to be defined.

Explanation of Solution

According to Arrhenius theory, an acid dissolves in water, it dissociates to produce hydrogen ions or protons (${\text{H}}^{\text{+}}$).  For example, hydrochloric acid dissociates in aqueous solution as given below.

    ${\text{HCl}}_{\text{(aq)}}\underset{}{\to }{\text{ H}}^{\text{+}}{}_{\text{(aq)}}{\text{ + Cl}}^{\text{-}}{}_{\text{(aq)}}$

(b)

Interpretation Introduction

Interpretation:

According to Bronsted-Lowry theory, an acid has to be defined.

Explanation of Solution

According to Bronsted-Lowry theory, an acid is a proton donor.  For example, hydrochloric acid in aqueous solution donates a proton to water, which results in formation of hydronium ion.

    ${\text{HCl}}_{\text{(aq)}}{\text{ + H}}_{\text{2}}{\text{O}}_{\text{(l)}}\underset{}{\to }{\text{ H}}_{\text{3}}{\text{O}}^{\text{+}}{}_{\text{(aq)}}{\text{ + Cl}}^{\text{-}}{}_{\text{(aq)}}$