Chapter 18, Problem 57A

Classify each compound as an Arrhenius acid or an Arrhenius base

1. ${\text{H}}_2\text{S}$
2. $\text{RbOH}$
3. $\text{Mg}{(\text{OH})}_2$
4. ${\text{H}}_3{\text{PO}}_4$

Interpretation Introduction

(a)

Interpretation:

The given compound is to be classified as Arrhenius acid or base.

Concept introduction:

According to Arrhenius,

Acid is a substance which gives hydrogen ion and Base is a substance which gives hydroxyl ions in aqueous solution.

Answer to Problem 57A

Arrhenius acid

Explanation of Solution

$H_{2}S$ionizes in water as:

$H_{2}S\rightleftharpoons 2H^{+}+S^{2-}$

It gives hydrogen ion. So it is acid.

Interpretation Introduction

(b)

Interpretation:

The given compound is to be classified as Arrhenius acid or base.

Concept introduction:

According to Arrhenius,

Acid is a substance which gives hydrogen ion and Base is a substance which gives hydroxyl ions in aqueous solution.

Answer to Problem 57A

Arrhenius base

Explanation of Solution

$RbOH$ionizes in water as:

$RbOH\rightleftharpoons R{b}^{+}+O{H}^{-}$

It gives hydroxyl ion. So it is base.

Interpretation Introduction

(c)

Interpretation:

The given compound is to be classified as Arrhenius acid or base.

Concept introduction:

According to Arrhenius,

Acid is a substance which gives hydrogen ion and Base is a substance which gives hydroxyl ions in aqueous solution.

Answer to Problem 57A

Arrhenius base

Explanation of Solution

$RbOH$ionizes in water as:

$Mg{\left(OH\right)}_2\rightleftharpoons M{g}^{2+}+2O{H}^{-}$

It gives hydroxyl ion. So it is base.

Interpretation Introduction

(d)

Interpretation:

The given compound is to be classified as Arrhenius acid or base.

Concept introduction:

According to Arrhenius,

Acid is a substance which gives hydrogen ion and Base is a substance which gives hydroxyl ions in aqueous solution.

Answer to Problem 57A

Arrhenius acid

Explanation of Solution

$H_{3}P{O}_4$ionizes in water as:

$H_{3}P{O}_4\rightleftharpoons 3H^{+}+P{O}_4{}^{3-}$

It gives hydrogen ion. So it is acid.