Chapter 19, Problem 79A

Interpretation Introduction

Interpretation : Lewis’s theory is a more general classification system than either the Arrhenius descriptions or the Bronsted-Lowry theory to be explained.

Concept Introduction : Acids are used to produce hydrogen ions by ionization. Bases are used to produce hydroxide ions by ionization.

Answer to Problem 79A

Lewis’s theory is a more general classification system than either the Arrhenius descriptions or the Bronsted-Lowry theory because he defined an acid as an electron-pair acceptor and a base as an electron-pair donor.

Explanation of Solution

Acids, according to Arrhenius, are substances that contain hydrogen and ionize to produce hydrogen ions $\left({\text{H}}^{\text{+}}\right)$ in an aqueous solution.

Bases are substances that ionize in aqueous solutions to produce hydroxide ions $\left({\text{OH}}^{-}\right)$ .

According to Bronsted-Lowry theory, a hydrogen ion that acts as a donor is an acid while a hydrogen ion that acts as an acceptor is a base.

According to Lewis’s theory, during a reaction, an acid takes in a pair of electrons and a base indicates a pair of electrons.

Since Lewis’s theory gives a simple definition as well as an apt definition for acid and base it is used more commonly than other theories.

Lewis defined an acid as an electron-pair acceptor and a base as an electron-pair donor.

It includes all the acids and bases of Bronsted-Lowry acids and bases.

A chemical that can receive two electrons to create a covalent bond is known as a Lewis acid.

A chemical known as a Lewis base can signify a pair of electrons to create a covalent bond.