Chapter 12, Problem 12.44QP

(a)

Interpretation Introduction

Interpretation:

From the given compounds, ionic, metallic ,molecular solids and covalent solids have to be identified.

${\text{(a) CO}}_2{\text{ (b) B}}_{12}{\text{(c) S}}_8{\text{(d) KBr (e) Mg (f) SiO}}_2\text{(g) LiCl (h) Cr}$

Concept Introduction:

Ionic solids constitute of ions of opposite charges.  Molecular solids are formed by covalent molecules which are either polar or non-polar.  Covalent solids are formed by atoms of same non-metallic elements and non-polar molecules.  The atoms that are capable of forming repeated chain-like bonding form covalent solids. The repetitive bonding results in three dimensional macro structures.  Metallic solids are composed of metal atoms in which they exist as positively charged ions amidst of pool of electrons.  The pool of electrons are nothing but the electrons lost by the metal atoms and they are delocalized in the entire crystal lattice.

Explanation of Solution

${\text{CO}}_{\text{2}}$ is a non-polar covalent compound. Non-polar covalent compounds have weak London dispersion force and it exists as Molecular solid.

(b)

Interpretation Introduction

Interpretation:

From the given compounds, ionic, metallic ,molecular solids and covalent solids have to be identified.

${\text{(a) CO}}_2{\text{ (b) B}}_{12}{\text{(c) S}}_8{\text{(d) KBr (e) Mg (f) SiO}}_2\text{(g) LiCl (h) Cr}$

Concept Introduction:

Ionic solids constitute of ions of opposite charges.  Molecular solids are formed by covalent molecules which are either polar or non-polar.  Covalent solids are formed by atoms of same non-metallic elements and non-polar molecules.  The atoms that are capable of forming repeated chain-like bonding form covalent solids. The repetitive bonding results in three dimensional macro structures.  Metallic solids are composed of metal atoms in which they exist as positively charged ions amidst of pool of electrons.  The pool of electrons are nothing but the electrons lost by the metal atoms and they are delocalized in the entire crystal lattice.

Explanation of Solution

Boron is capable of forming repeated, continuous covalent bonds.  Thus in ${\text{B}}_{12}$ Boron atoms bond among between each other covalently and forms a three-dimensional macrostructure. It is covalent solid.

(c)

Interpretation Introduction

Interpretation:

From the given compounds, ionic, metallic ,molecular solids and covalent solids have to be identified.

${\text{(a) CO}}_2{\text{ (b) B}}_{12}{\text{(c) S}}_8{\text{(d) KBr (e) Mg (f) SiO}}_2\text{(g) LiCl (h) Cr}$

Concept Introduction:

Ionic solids constitute of ions of opposite charges.  Molecular solids are formed by covalent molecules which are either polar or non-polar.  Covalent solids are formed by atoms of same non-metallic elements and non-polar molecules.  The atoms that are capable of forming repeated chain-like bonding form covalent solids. The repetitive bonding results in three dimensional macro structures.  Metallic solids are composed of metal atoms in which they exist as positively charged ions amidst of pool of electrons.  The pool of electrons are nothing but the electrons lost by the metal atoms and they are delocalized in the entire crystal lattice.

Explanation of Solution

${\text{S}}_8$ is eight atoms of Sulfur bond together and form a molecule. Sulfur is a non-metal and its majority of compounds are covalent.  Sulfur is not capable of forming repeated, continuous covalent bonds. Thus it does not form Covalent solids instead they form molecular solids. Hence ${\text{S}}_8$is molecular solid.

(d)

Interpretation Introduction

Interpretation:

From the given compounds, ionic, metallic ,molecular solids and covalent solids have to be identified.

${\text{(a) CO}}_2{\text{ (b) B}}_{12}{\text{(c) S}}_8{\text{(d) KBr (e) Mg (f) SiO}}_2\text{(g) LiCl (h) Cr}$

Concept Introduction:

Ionic solids constitute of ions of opposite charges.  Molecular solids are formed by covalent molecules which are either polar or non-polar.  Covalent solids are formed by atoms of same non-metallic elements and non-polar molecules.  The atoms that are capable of forming repeated chain-like bonding form covalent solids. The repetitive bonding results in three dimensional macro structures.  Metallic solids are composed of metal atoms in which they exist as positively charged ions amidst of pool of electrons.  The pool of electrons are nothing but the electrons lost by the metal atoms and they are delocalized in the entire crystal lattice.

Explanation of Solution

In $\text{KBr}$, Potassium and bromide ions are held together by ionic bond. It is ionic solid.

The electronegative value of Potassium and Bromine are quite different with respect to each other.  Potassium is highly electropositive and capable of forming positively charged ions and Bromine is electronegative element and forms negatively charged ion. the ions of opposite charges held together by ionic bond.  Hence, $\text{KBr}$is ionic solid.

(e)

Interpretation Introduction

Interpretation:

From the given compounds, ionic, metallic ,molecular solids and covalent solids have to be identified.

${\text{(a) CO}}_2{\text{ (b) B}}_{12}{\text{(c) S}}_8{\text{(d) KBr (e) Mg (f) SiO}}_2\text{(g) LiCl (h) Cr}$

Concept Introduction:

Ionic solids constitute of ions of opposite charges.  Molecular solids are formed by covalent molecules which are either polar or non-polar.  Covalent solids are formed by atoms of same non-metallic elements and non-polar molecules.  The atoms that are capable of forming repeated chain-like bonding form covalent solids. The repetitive bonding results in three dimensional macro structures.  Metallic solids are composed of metal atoms in which they exist as positively charged ions amidst of pool of electrons.  The pool of electrons are nothing but the electrons lost by the metal atoms and they are delocalized in the entire crystal lattice.

Explanation of Solution

Magnesium is a highly electropositive metal. it forms dipositive ion by losing its two valence electrons. Thus it forms metallic solids in which it exists as numerous ${\text{Mg}}^{2+}$ ions amidst of pool of electrons.

(f)

Interpretation Introduction

Interpretation:

From the given compounds, ionic, metallic ,molecular solids and covalent solids have to be identified.

${\text{(a) CO}}_2{\text{ (b) B}}_{12}{\text{(c) S}}_8{\text{(d) KBr (e) Mg (f) SiO}}_2\text{(g) LiCl (h) Cr}$

Concept Introduction:

Ionic solids constitute of ions of opposite charges.  Molecular solids are formed by covalent molecules which are either polar or non-polar.  Covalent solids are formed by atoms of same non-metallic elements and non-polar molecules.  The atoms that are capable of forming repeated chain-like bonding form covalent solids. The repetitive bonding results in three dimensional macro structures.  Metallic solids are composed of metal atoms in which they exist as positively charged ions amidst of pool of electrons.  The pool of electrons are nothing but the electrons lost by the metal atoms and they are delocalized in the entire crystal lattice.

Explanation of Solution

Silicon is capable of forming repeated, continuous covalent bonds . Thus ${\text{SiO}}_2$ exists as Covalent solid.

(g)

Interpretation Introduction

Interpretation:

From the given compounds, ionic, metallic ,molecular solids and covalent solids have to be identified.

${\text{(a) CO}}_2{\text{ (b) B}}_{12}{\text{(c) S}}_8{\text{(d) KBr (e) Mg (f) SiO}}_2\text{(g) LiCl (h) Cr}$

Concept Introduction:

Ionic solids constitute of ions of opposite charges.  Molecular solids are formed by covalent molecules which are either polar or non-polar.  Covalent solids are formed by atoms of same non-metallic elements and non-polar molecules.  The atoms that are capable of forming repeated chain-like bonding form covalent solids. The repetitive bonding results in three dimensional macro structures.  Metallic solids are composed of metal atoms in which they exist as positively charged ions amidst of pool of electrons.  The pool of electrons are nothing but the electrons lost by the metal atoms and they are delocalized in the entire crystal lattice.

Explanation of Solution

The electronegative value of Lithium and Chlorine are quite different with respect to each other.  Lithium is highly electropositive and capable of forming positively charged ions and Chlorine is highly electronegative element and forms negatively charged ion. the ions of opposite charges held together by ionic bond.  Hence, $\text{LiCl}$ is ionic solid.

(h)

Interpretation Introduction

Interpretation:

From the given compounds, ionic, metallic ,molecular solids and covalent solids have to be identified.

${\text{(a) CO}}_2{\text{ (b) B}}_{12}{\text{(c) S}}_8{\text{(d) KBr (e) Mg (f) SiO}}_2\text{(g) LiCl (h) Cr}$

Concept Introduction:

Ionic solids constitute of ions of opposite charges.  Molecular solids are formed by covalent molecules which are either polar or non-polar.  Covalent solids are formed by atoms of same non-metallic elements and non-polar molecules.  The atoms that are capable of forming repeated chain-like bonding form covalent solids. The repetitive bonding results in three dimensional macro structures.  Metallic solids are composed of metal atoms in which they exist as positively charged ions amidst of pool of electrons.  The pool of electrons are nothing but the electrons lost by the metal atoms and they are delocalized in the entire crystal lattice.

Explanation of Solution

Chromium is a electropositive metal.  It forms positive ion by losing its two valence electrons.  Thus it forms metallic solids in which it exists as numerous ions amidst of pool of electrons.

Conclusion

From the given compounds, the Ionic solids are – $\text{KBr,}\text{LiCl}$.

Covalent solids are – ${\text{SiO}}_{\text{2}}\text{and}{\text{B}}_{\text{12}}\text{.}$

Molecular solids are – ${\text{CO}}_{\text{2}}\text{,}{\text{S}}_{\text{8}}$.

Metallic solids are - $\text{Mg, Cr}\text{.}$