Chapter 7, Problem 79A

(a)

Interpretation Introduction

Interpretation : The A-group number to which element X belong is to be identified.

Concept Introduction : Cations and anions combine to form an ionic compound.

The cation of metal and anion of non-metal are the main components of ionic compounds.

Answer to Problem 79A

Element X belongs to the 6A group number.

Explanation of Solution

Even though ionic compounds are formed of ions, they have no electrical charge.

The smallest whole-number ratio of ions in an ionic compound is known as a formula unit.

The given formula is $\text{CaX}$ .

Since calcium is a metal belonging to the 2A group it will lose 2 electrons to form an octet configuration.

The formed cation from calcium is ${\text{Ca}}^{2+}$ .

The anion should be ${\text{X}}^{\text{2}-}$ where the non-metal will gain 2 electrons to form an octet.

So, the group number will be 6A group.

(b)

Interpretation Introduction

Interpretation : The A-group number to which element X belong is to be identified.

Concept Introduction : Cations and anions combine to form an ionic compound.

The cation of metal and anion of non-metal are the main components of ionic compounds.

Answer to Problem 79A

Element X belongs to the 7A group number.

Explanation of Solution

Even though ionic compounds are formed of ions, they have no electrical charge. The smallest whole-number ratio of ions in an ionic compound is known as a formula unit.

The given formula is ${\text{MgX}}_2$ .

Since magnesium is a metal belonging to the 2A group it will lose 2 electrons to form an octet configuration.

The formed cation from calcium is ${\text{Mg}}^{2+}$ .

The anion should be ${\text{2X}}^{-}$ where there are two non-metals each will gain 1 electron to form an octet.

So, the group number will be 7A group.

(c)

Interpretation Introduction

Interpretation : The A-group number to which element X belong is to be identified.

Concept Introduction : Cations and anions combine to form an ionic compound.

The cation of metal and anion of non-metal are the main components of ionic compounds.

Answer to Problem 79A

The element X belongs to 1A group number.

Explanation of Solution

Even though ionic compounds are formed of ions, they have no electrical charge. The smallest whole-number ratio of ions in an ionic compound is known as a formula unit.

The given formula is ${\text{X}}_{\text{3}}\text{N}$ .

Since nitrogen is a non-metal belonging to the 5A group it will gain 3 electrons to form an octet configuration.

The formed anion from nitrogen is ${\text{N}}^{3-}$ .

The cation should be ${\text{3X}}^{+}$ where there are three metals each will lose 1 electron to form an octet.

So, the group number will be 1A group.

(d)

Interpretation Introduction

Interpretation : The A-group number to which element X belong is to be identified.

Concept Introduction : Cations and anions combine to form an ionic compound.

The cation of metal and anion of non-metal are the main components of ionic compounds.

Answer to Problem 79A

Element X belongs to 6A group number.

Explanation of Solution

Even though ionic compounds are formed of ions, they have no electrical charge.

The smallest whole-number ratio of ions in an ionic compound is known as a formula unit.

The given formula is ${\text{Al}}_{\text{2}}{\text{X}}_{\text{3}}$ .

Since aluminum is a metal belonging to the 3A group each of it will lose 3 electrons to form an octet configuration.

The formed cation from aluminium is $2{\text{Al}}^{3+}$ .

The anion should be ${\text{3X}}^{\text{2}-}$ where the non-metal each will gain two 2 electrons to form an octet.

So, the group number will be 6A group.

(e)

Interpretation Introduction

Interpretation : The A-group number to which element X belong is to be identified.

Concept Introduction : Cations and anions combine to form an ionic compound.

The cation of metal and anion of non-metal are the main components of ionic compounds.

Answer to Problem 79A

The element X belongs to 1A group number.

Explanation of Solution

Even though ionic compounds are formed of ions, they have no electrical charge. The smallest whole-number ratio of ions in an ionic compound is known as a formula unit.

The given formula is $\text{XF}$ .

Since fluorine is a non-metal belonging to the 7A group it will gain 1 electron to form an octet configuration.

The formed anion from fluorine is ${\text{F}}^{-}$ .

The cation should be ${\text{X}}^{+}$ where the metal will lose 1 electron to form an octet.

So, the group number will be 1A group.

(f)

Interpretation Introduction

Interpretation : The A-group number to which element X belong is to be identified.

Concept Introduction : Cations and anions combine to form an ionic compound.

The cation of metal and anion of non-metal are the main components of ionic compounds.

Answer to Problem 79A

The element X belongs to 2A group number.

Explanation of Solution

Even though ionic compounds are formed of ions, they have no electrical charge. The smallest whole-number ratio of ions in an ionic compound is known as a formula unit.

The given formula is $\text{XS}$ .

Since sulphide is a non-metal belonging to the 6A group it will gain 2 electrons to form an octet configuration.

The formed anion from sulphide is ${\text{S}}^{2-}$ .

The cation should be ${\text{X}}^{\text{2+}}$ where the metal will lose 2 electrons to form an octet.

So, the group number will be 2A group.