Chapter 9.1, Problem 7LC

(a)

Interpretation Introduction

Interpretation: The symbol or formula for the ion is to be identified.

Concept Introduction : There are two types of charged species, anion (negatively charged species) and cation (positively charged species). Anion is formed by the gaining of electron/s whereas a cation is formed by losing electron/s.

Answer to Problem 7LC

The given ion has a +1 charge, and its symbol is ${\text{NH}}_4{}^{+}$ .

Explanation of Solution

The given ion is an ammonium ion. It is formed when ammonia gains one hydrogen atom. Thus, it has 1 N and 4 H atoms. It has a +1 charge, and its symbol is ${\text{NH}}_4{}^{+}$ .

(b)

Interpretation Introduction

Interpretation: The symbol or formula for the ion is to be identified.

Concept Introduction : There are two types of charged species, anion (negatively charged species) and cation (positively charged species). Anion is formed by the gaining of electron/s whereas a cation is formed by losing electron/s.

Answer to Problem 7LC

The given ion has a +2 charge, and its symbol is ${\text{Cr}}^{2+}$ .

Explanation of Solution

The given ion is the chromium (II) ion. Here, the oxidation state of Cr is +2; thus, it has a +2 charge, and its symbol is ${\text{Cr}}^{2+}$ .

(c)

Interpretation Introduction

Interpretation: The symbol or formula for the ion is to be identified.

Concept Introduction : There are two types of charged species, anion (negatively charged species) and cation (positively charged species). Anion is formed by the gaining of electron/s whereas a cation is formed by losing electron/s.

Answer to Problem 7LC

The given ion has a -2 charge, and its symbol is ${\text{CrO}}_4{}^{2-}$ .

Explanation of Solution

The given ion is a chromate ion. There is 1 Cr atom and 4 O atoms in the ion. Also, it has a -2 charge. Thus, its symbol is ${\text{CrO}}_4{}^{2-}$ .

(d)

Interpretation Introduction

Interpretation: The symbol or formula for the ion is to be identified.

Concept Introduction : There are two types of charged species, anion (negatively charged species) and cation (positively charged species). Anion is formed by the gaining of electron/s whereas a cation is formed by losing electron/s.

Answer to Problem 7LC

The given ion has a -1 charge, and its symbol is ${\text{NO}}_3{}^{-}$ .

Explanation of Solution

The given ion is the nitrate ion. It has 1 N and 3 O atoms. The overall charge on the ion is -1 charge, and its symbol is ${\text{NO}}_3{}^{-}$ .