Chapter 19, Problem 66A

a.

Interpretation Introduction

Interpretation : The given compound is a strong or weak acid or base to be identified.

Concept Introduction : Acids 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 $\left({\text{OH}}^{-}\right)$ .

Answer to Problem 66A

The compound $\text{NaOH}$ is a strong base.

Explanation of Solution

Based on the amount they ionize in water, acids and bases are categorized as strong or weak.

The given compound is $\text{NaOH}$ .

It is a strong base.

In an aqueous solution, a strong base completely dissociates into metal ions and hydroxide ions.

The sodium hydroxide dissociates into sodium metal ions and hydroxide ions.

b.

Interpretation Introduction

Interpretation : The given compound is a strong or weak acid or base to be identified.

Concept Introduction : Acids 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 $\left({\text{OH}}^{-}\right)$ .

Answer to Problem 66A

The compound ${\text{NH}}_3$ is a weak base.

Explanation of Solution

Based on the amount they ionize in water, acids and bases are categorized as strong or weak.

The given compound is ${\text{NH}}_3$ .

It is a weak base.

In an aqueous solution, a weak base only dissociates to a small amount giving hydroxide ions and conjugate acid of the base.

  ${\text{NH}}_3$ in aqueous solution gives ammonium ions and hydroxide ions.

  ${\text{NH}}_3\left(aq\right)+{\text{H}}_{\text{2}}\text{O}\left(l\right)\rightleftharpoons {\text{NH}}_{\text{4}}^{\text{+}}\left(aq\right)+{\text{OH}}^{-}\left(aq\right)$

The ammonium ion is the conjugate acid of the base ammonia.

c.

Interpretation Introduction

Interpretation : The given compound is a strong or weak acid or base to be identified.

Concept Introduction : Acids 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 $\left({\text{OH}}^{-}\right)$ .

Answer to Problem 66A

The compound ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$ is a strong acid.

Explanation of Solution

Based on the amount they ionize in water, acids and bases are categorized as strong or weak.

The given compound is ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$ .

It is a strong acid.

In water, a strong acid totally ionizes.

The sulphuric acid ionizes completely to give hydronium ions.

  ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}\left(aq\right)+{\text{H}}_{\text{2}}\text{O}\left(l\right)\to {\text{H}}_{\text{3}}{\text{O}}^{\text{+}}\left(aq\right)+{\text{HSO}}_4^{-}\left(aq\right)$

d.

Interpretation Introduction

Interpretation : The given compound is a strong or weak acid or base to be identified.

Concept Introduction : Acids 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 $\left({\text{OH}}^{-}\right)$ .

Answer to Problem 66A

The compound $\text{HCl}$ is a strong acid.

Explanation of Solution

Based on the amount they ionize in water, acids and bases are categorized as strong or weak.

The given compound is $\text{HCl}$ .

It is a strong acid.

In water, a strong acid totally ionizes.

The hydrochloric acid ionizes completely to give hydronium ions.

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