Chapter 14.3, Problem 5RQ

(a)

Interpretation Introduction

Interpretation: The type of crystalline solid of sulfur needs to be determined.

Concept Introduction: A crystalline solid is characterized by regular arrangement of its components. There are many types of crystalline solids such as ionic solids, molecular solids, covalent network solids, and metallic solids.

Answer to Problem 5RQ

Sulfur is a molecular solids.

Explanation of Solution

In a molecular solid the fundamental particle is a molecule which is held by intermolecular forces like dipole-dipole or London dispersion force or hydrogen bonding. Sulfur (contains $S_8$ molecules) are held together by only London dispersion force because it is a non-polar molecule.

(b)

Interpretation Introduction

Interpretation: The type of crystalline solid of dry ice needs to be determined.

Concept Introduction: A crystalline solid is characterized by regular arrangement of its components. There are many types of crystalline solids such as ionic solids, molecular solids, covalent network solids, and metallic solids.

Answer to Problem 5RQ

Dry ice (solid $C{O}_2$ ) is a molecular solids.

Explanation of Solution

In a molecular solid the fundamental particle is a molecule which is held by intermolecular forces like dipole-dipole or London dispersion force or hydrogen bonding. In $C{O}_2$ the dipole of $C-O$ acts in opposite direction and hence they cancel each other. Despite $C{O}_2$ has polar bond, it is a non-polar molecule having London dispersion force as a prime intermolecular force.

(c)

Interpretation Introduction

Interpretation: The type of crystalline solid of potassium nitrate ( $KN{O}_3$ ) needs to be determined.

Concept Introduction: A crystalline solid is characterized by regular arrangement of its components. There are many types of crystalline solids such as ionic solids, molecular solids, covalent network solids, and metallic solids.

Answer to Problem 5RQ

Potassium nitrate ( $KN{O}_3$ ) is an ionic solid.

Explanation of Solution

Ionic solids are held together by the strong forces that exist between oppositely charged ions. $KN{O}_3$ consists of positively charged $K^{+}$ and negatively charged $N{O}_3^{-}$ held together by strong electrostatic or coulombic force of attraction.

(d)

Interpretation Introduction

Interpretation: The type of crystalline solid of gold needs to be determined.

Concept Introduction: A crystalline solid is characterized by regular arrangement of its components. There are many types of crystalline solids such as ionic solids, molecular solids, covalent network solids, and metallic solids.

Answer to Problem 5RQ

Gold ( $Au$ ) is a metallic solid.

Explanation of Solution

Metallic solids can be defined as a solid consisting of metal atoms that stick together by strong metallic bonds. In gold, metal cations ( $A{u}^{+}$ ) are surrounded by a "sea" of mobile valence electrons which can freely move in entire crystal lattice and are not localized.