Chapter 5.4, Problem 5.4WE

(a)

Interpretation Introduction

Interpretation: The respective formulae for the given compounds should be identified.

Concept Introduction:

In the formula of the compound, the sum cation and anionic charges must be equal to zero. The ratio of cation and anion should be known in order to deduce the formula of a compound.

Rules for Nomenclature of ionic compounds:

• The name of the cation is followed by the name of the anion.

Cation: Removal of electron from the atom results to form positively charged ion called cation.

Anion: Addition of electron to atom results to form negatively charged ion called anion.

The net charge present in the element denotes the presence or absence of electrons in the element.

Answer to Problem 5.4WE

$\begin{array}{l}\text{Name : Mercury(II) chloride}\text{. }\\ {\text{Formula : HgCl}}_{\text{2}}\end{array}$

Explanation of Solution

Predict the Formula.

$\begin{array}{l}\text{a) Name : Mercury(II) chloride}\text{.}\\ \text{ Cation: Mercury}\\ \text{ Anion: chloride}\text{.}\\ \text{Instruction follows:}\\ \text{ 1) Write}\text{cation's}2)\text{Write}\text{anion's}3)\text{Combine}\text{ions}\\ \text{symbol}\text{and}\text{symbol}\text{and}\text{in}\text{neutral}\text{ratio}\text{.}\\ \text{charge}\text{.}\text{charge}\text{.}\\ {\text{ Hg}}^{\text{2+}}{\text{Cl}}^{\text{-}}{\text{HgCl}}_{\text{2}}\\ \\ \boxed{\text{The formula is: }{\text{HgCl}}_{\text{2}}.}\end{array}$

The cation and anion along with the charges are determined as above. Finally the symbols for the ions are combined. The sum of the charges of both cation and anion is equal to zero when the ratio of combination is $\text{1:2}$ that is there exist one mercury cation and two chloride anions.

(b)

Interpretation Introduction

Interpretation: The respective formulae for the given compounds should be identified.

Concept Introduction:

In the formula of the compound, the sum cation and anionic charges must be equal to zero. The ratio of cation and anion should be known in order to deduce the formula of a compound.

Rules for Nomenclature of ionic compounds:

• The name of the cation is followed by the name of the anion.

Cation: Removal of electron from the atom results to form positively charged ion called cation.

Anion: Addition of electron to atom results to form negatively charged ion called anion.

The net charge present in the element denotes the presence or absence of electrons in the element.

Answer to Problem 5.4WE

$\begin{array}{l}\text{Name : Lead(II) bromide}\text{.}\\ {\text{Formula : PbBr}}_{\text{2}}\end{array}$

Explanation of Solution

Predict the Formula.

$\begin{array}{l}\text{b) Name : Lead(II) bromide}\text{.}\\ \text{ Cation: lead}\\ \text{ Anion: bromide}\text{.}\\ \text{Instruction follows:}\\ \text{ 1) Write}\text{cation's}2)\text{Write}\text{anion's}3)\text{Combine}\text{ions}\\ \text{symbol}\text{and}\text{symbol}\text{and}\text{in}\text{neutral}\text{ratio}\text{.}\\ \text{charge}\text{.}\text{charge}\text{.}\\ {\text{ Pb}}^{\text{2+}}{\text{Br}}^{\text{-}}{\text{PbBr}}_{\text{2}}\\ \\ \boxed{\text{The formula is: }{\text{PbBr}}_{\text{2}}.}\end{array}$

The cation and anion along with the charges are determined as above. Finally the ions are combined in neutral ratio. The sum of the charge of both cation and anion is equal to zero when the ratio of combination is $\text{1:2}$ that is there exist one lead cation and two bromide anions.

(c)

Interpretation Introduction

Interpretation: The respective formulae for the given compounds should be identified.

Concept Introduction:

In the formula of the compound, the sum cation and anionic charges must be equal to zero. The ratio of cation and anion should be known in order to deduce the formula of a compound.

Rules for Nomenclature of ionic compounds:

• The name of the cation is followed by the name of the anion.

Cation: Removal of electron from the atom results to form positively charged ion called cation.

Anion: Addition of electron to atom results to form negatively charged ion called anion.

The net charge present in the element denotes the presence or absence of electrons in the element.

Answer to Problem 5.4WE

$\begin{array}{l}\text{Name : Potassium nitride}\\ {\text{Formula : K}}_3\text{N}\text{.}\end{array}$

Explanation of Solution

Predict the Formula.

$\begin{array}{l}\text{c) Name : Potassium nitride}\text{.}\\ \text{ Cation: Potassium}\\ \text{ Anion: nitride}\text{.}\\ \text{Instruction follows:}\\ \text{ 1) Write}\text{cation's}2)\text{Write}\text{anion's}3)\text{Combine}\text{ions}\\ \text{symbol}\text{and}\text{symbol}\text{and}\text{in}\text{neutral}\text{ratio}\text{.}\\ \text{charge}\text{.}\text{charge}\text{.}\\ {\text{ K}}^{\text{+}}{\text{N}}^{\text{3-}}{\text{K}}_3\text{N}\\ \\ \boxed{\text{The formula is: }{\text{K}}_3\text{N}\text{.}}\end{array}$

The cation and anion along with the charges are predicted as above. Finally the ions are combined in neutral ratio. The sum of the charges of both cation and anion is equal to zero when the ratio of combination is $\text{3:1}$ that is there exist three potassium cation and one nitride anion are present.