Chapter 4, Problem 3RQ

Consider the following compounds: CO₂, SO₂, KrF₂, SO₃, NF₃, IF₃, CF₄, SF₄, XeF₄, PF₅, TF₅, and SCl₆. These 12 compounds are all examples of different molecular structures. Draw the Lewis structures for each and predict the molecular structures. Predict the bond angles and the polarity of each. (A polar molecule has a net dipole moment, while a nonpolar molecule does not.) See Exercises 25 and 26 for the molecular structures based on the trigonal bipyramid and the octahedral geometries.

Interpretation Introduction

Interpretation: The Lewis structure, bond angles and polarity of the given compounds is to be stated.

Concept introduction: Gilbert Newton Lewis introduced the Lewis dot structure or electron dot structure theory to describe the concept of covalent bond. Lewis structure states the total valence electrons, bonded electrons and lone pair of electrons a chemical species has. The geometry, bond angles and polarity of any chemical species depends upon its Lewis dot structure. Generally octet is followed by Lewis dot structures.

Explanation of Solution

Explanation

For ${\text{CO}}_2$ molecule the central atom is carbon, which has $6$ total electrons out of which $4$ electrons are present in valence orbit. The electronic configuration of carbon is,

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{2}}$

The oxygen atom has $8$ total electrons out of which $6$ electrons are present in valence orbit. The electronic configuration of oxygen is,

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{4}}$

In order to satisfy the octet rule the most probable Lewis dot structure of ${\text{CO}}_2$ is shown by Figure 1. The geometry of ${\text{CO}}_2$ is linear with bond angle $180°$. ${\text{CO}}_2$ is an non-polar compound.

Figure 1

For ${\text{SO}}_2$ molecule the central atom is Sulfur which has $16$ total electrons out of which $6$ electrons are present in valence orbit. The electronic configuration of Sulfur is,

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{6}}{\text{3s}}^{\text{2}}{\text{3p}}^{\text{4}}$

The oxygen atom has $8$ total electrons out of which $6$ electrons are present in valence orbit. The electronic configuration of oxygen is,

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{4}}$

In order to satisfy the octet rule the most probable Lewis dot structure of ${\text{SO}}_2$ is shown by Figure 2 The geometry of ${\text{SO}}_2$ is bent with bond angle $120°$. ${\text{SO}}_2$ is a polar compound.

Figure 2

For ${\text{KrF}}_2$ molecule the central atom is Krypton which has $32$ total electrons out of which $8$ electrons are present in valence orbit. The electronic configuration of Krypton is,

$\left[\text{Ar}\right]{\text{4s}}^{\text{2}}{\text{4p}}^{\text{4}}$

The Fluorine atom has $9$ total electrons out of which $7$ electrons are present in valence orbit. The electronic configuration of oxygen is,

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{5}}$

In order to satisfy the octet rule the most probable Lewis dot structure of ${\text{KrF}}_2$ is shown by Figure 3 The geometry of ${\text{KrF}}_2$ is linear with bond angle $180°$. ${\text{KrF}}_2$ is a non-polar compound.

Figure 3

For ${\text{SO}}_3$ molecule the central atom is Sulfur which has $16$ total electrons out of which $6$ electrons are present in valence orbit. The electronic configuration of Sulfur is,

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{6}}{\text{3s}}^{\text{2}}{\text{3p}}^{\text{4}}$

The oxygen atom has $8$ total electrons out of which $6$ electrons are present in valence orbit. The electronic configuration of oxygen is,

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{4}}$

In order to satisfy the octet rule the most probable Lewis dot structure of ${\text{SO}}_3$ is shown by Figure $4$ The geometry of ${\text{SO}}_3$ is trigonal planer with bond angle $120°$. ${\text{SO}}_2$ is a non- polar compound.

Figure 4

For ${\text{NF}}_3$ molecule the central atom is Nitrogen which has $8$ total electrons out of which $5$ electrons are present in valence orbit. The electronic configuration of Nitrogen is,

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{3}}$

The Fluorine atom has $9$ total electrons out of which $7$ electrons are present in valence orbit. The electronic configuration of oxygen is,

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{5}}$

In order to satisfy the octet rule the most probable Lewis dot structure of ${\text{NF}}_3$ is shown by Figure $5$  The geometry of ${\text{NF}}_3$ is pyramidal with bond angle $104°$. ${\text{NF}}_3$ is a polar compound.

Figure 5

For ${\text{IF}}_3$ molecule the central atom is Iodine which has $53$ total electrons out of which $7$ electrons are present in valence orbit. The electronic configuration of Iodine is,

$\left[\text{Kr}\right]{\text{4d}}^{\text{10}}{\text{5s}}^{\text{2}}{\text{5p}}^{\text{5}}$

The Fluorine atom has $9$ total electrons out of which $7$ electrons are present in valence orbit. The electronic configuration of oxygen is,

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{5}}$

In order to satisfy the octet rule the most probable Lewis dot structure of ${\text{IF}}_3$ is shown by Figure $6$ The geometry of ${\text{IF}}_3$ is T-shape with bond angle $90°$. ${\text{IF}}_3$ is a polar compound.

Figure 6

For ${\text{CF}}_4$ molecule the central atom is Carbon which has $6$ total electrons out of which $4$ electrons are present in valence orbit. The electronic configuration of Carbon is,

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{2}}$

The Fluorine atom has $9$ total electrons out of which $7$ electrons are present in valence orbit. The electronic configuration of oxygen is,

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{5}}$

In order to satisfy the octet rule the most probable Lewis dot structure of ${\text{CF}}_4$ is shown by Figure $7$  The geometry of ${\text{CF}}_4$ is tetrahedral with bond angle $109°$. ${\text{CF}}_4$ is a non-polar compound.

Figure $7$

For ${\text{SF}}_4$ molecule the central atom is Sulfur which has $16$ total electrons out of which $6$ electrons are present in valence orbit. The electronic configuration of Sulfur is,

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{6}}{\text{3s}}^{\text{2}}{\text{3p}}^{\text{4}}$

The Fluorine atom has $9$ total electrons out of which $7$ electrons are present in valence orbit. The electronic configuration of oxygen is,

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{5}}$

In order to satisfy the octet rule the most probable Lewis dot structure of ${\text{SF}}_4$ is shown by Figure $7$. The geometry of ${\text{SF}}_4$ is Seesaw with bond angle $90°$. ${\text{SF}}_4$ is a polar compound.

Figure $8$

For ${\text{XeF}}_4$ molecule the central atom is Xenon which has $54$ total electrons out of which $8$ electrons are present in valence orbit. The electronic configuration of Xenon is,

$\left[\text{Kr}\right]{\text{3d}}^{\text{10}}{\text{5s}}^{\text{2}}{\text{5p}}^{\text{6}}$

The Fluorine atom has $9$ total electrons out of which $7$ electrons are present in valence orbit. The electronic configuration of oxygen is,

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{5}}$

In order to satisfy the octet rule the most probable Lewis dot structure of ${\text{XeF}}_4$ is shown by Figure $9$. The geometry of ${\text{XeF}}_4$ is square planer with bond angle $90°$. ${\text{XeF}}_4$ is a polar compound.

Figure $9$

For ${\text{PF}}_5$ molecule the central atom is Phosphorus which has $15$ total electrons out of which $5$ electrons are present in valence orbit. The electronic configuration of Phosphorus is,

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{6}}{\text{3s}}^{\text{2}}{\text{3p}}^{\text{3}}$

The Fluorine atom has $9$ total electrons out of which $7$ electrons are present in valence orbit. The electronic configuration of oxygen is,

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{5}}$

In order to satisfy the octet rule the most probable Lewis dot structure of ${\text{PF}}_5$ is shown by Figure $10$. The geometry of ${\text{PF}}_5$ is trigonal bipyramidal with bond angle $90°$. ${\text{XeF}}_4$ is a non-polar compound.

Figure $10$

For ${\text{IF}}_5$ molecule the central atom is Iodine which has $53$ total electrons out of which $7$ electrons are present in valence orbit. The electronic configuration of Iodine is,

$\left[\text{Kr}\right]{\text{4d}}^{\text{10}}{\text{5s}}^{\text{2}}{\text{5p}}^{\text{5}}$

The Fluorine atom has $9$ total electrons out of which $7$ electrons are present in valence orbit. The electronic configuration of oxygen is,

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{5}}$

In order to satisfy the octet rule the most probable Lewis dot structure of ${\text{IF}}_5$ is shown by Figure $11$. The geometry of ${\text{IF}}_5$ is square-pyramidal with bond angle $90°$. ${\text{IF}}_5$ is a polar compound.

Figure $11$

For ${\text{SCl}}_6$ molecule the central atom is Sulfur which has $16$ total electrons out of which $6$ electrons are present in valence orbit. The electronic configuration of Sulfur is,

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{6}}{\text{3s}}^{\text{2}}{\text{3p}}^{\text{4}}$

The Chlorine atom has $17$ total electrons out of which $7$ electrons are present in valence orbit. The electronic configuration of Chlorine is,

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{6}}{\text{3s}}^{\text{2}}{\text{3p}}^{\text{5}}$

In order to satisfy the octet rule the most probable Lewis dot structure of ${\text{SCl}}_6$ is shown by Figure $12$ The geometry of ${\text{SCl}}_6$ is octahedral with bond angle $90°$. ${\text{SCl}}_6$ is a non-polar compound.

Figure $12$

Conclusion

Conclusion

• The Lewis dot structure of ${\text{CO}}_2$ has been stated above in figure $1$. Its shape is linear with the bond angle $180°$ and non-polar in nature.
• The Lewis dot structure of ${\text{SO}}_2$ has been stated above in figure $2$. Its shape is bent with the bond angle $120°$ and polar in nature.
• The Lewis dot structure of ${\text{KrF}}_2$ has been stated above in figure $3$. Its shape is linear with the bond angle $180°$ and non-polar in nature.
• The Lewis dot structure of ${\text{SO}}_3$ has been stated above in figure $4$. Its shape is trigonal planer with the bond angle $120°$ and non-polar in nature.
• The Lewis dot structure of ${\text{NF}}_3$ has been stated above in figure $5$. Its shape is pyramidal with the bond angle $104°$ and non-polar in nature.
• The Lewis dot structure of ${\text{IF}}_3$ has been stated above in figure $6$. Its shape is T-shape with the bond angle $90°$ and polar in nature.
• The Lewis dot structure of ${\text{CF}}_4$ has been stated above in figure $7$. Its shape is tetrahedral with the bond angle $109°$ and non-polar in nature.
• The Lewis dot structure of ${\text{SF}}_4$ has been stated above in figure $8$. Its shape is Seesaw with the bond angle $90°$ and polar in nature.
• The Lewis dot structure of ${\text{XeF}}_4$ has been stated above in figure $9$. Its shape is square planer with the bond angle $90°$ and polar in nature.
• The Lewis dot structure of ${\text{PF}}_5$ has been stated above in figure $10$. Its shape is trigonal bipyramidal with the bond angle $90°$ and non-polar in nature.
• The Lewis dot structure of ${\text{IF}}_5$ has been stated above in figure $11$. Its shape is square pyramidal with the bond angle $90°$ and polar in nature.
• The Lewis dot structure of ${\text{SCl}}_6$ has been stated above in figure $12$. Its shape is octahedral with the bond angle $90°$ and non- polar in nature