Chapter 1, Problem 1.22AP

Interpretation Introduction

(a)

Interpretation:

The non-hydrogen atom from the given species having a complete octet is to be stated. The formal charge on the atom is to be stated.

Concept introduction:

Chemical compounds contain two types of bonds. These are known as ionic and covalent bonds. In ionic bonds, the ions are held by the electrostatic interaction between them. In covalent bonds, the atoms are held together by the sharing of electrons. The formal charge is the charge on the constituent atoms in a molecule. It is calculated by using valence electrons of the atom.

Answer to Problem 1.22AP

The non-hydrogen atom in ${\text{CH}}_{\text{3}}$ molecule is carbon atom that does not have a complete octet. The formal charge on carbon atom is found to be $1$.

Explanation of Solution

The structure of ${\text{CH}}_{\text{3}}$ molecule is shown in figure 1.

Figure 1

From the above figure, it is clear that number of electrons around carbon atom is $6$. Thus, it is electron deficient and does not have complete octet. The group number for carbon atom is $4$. The formal charge on atom is calculated by the formula given below as,

$\text{Formal}\text{charge}=\text{Group}\text{number}-\text{valence}\text{electrons}$

The valence electrons of carbon atom in the ${\text{CH}}_{\text{3}}$ molecule is $3$. Substitute the values in above equation as follows.

$\begin{array}{rll}\text{Formal}\text{charge}& =& \text{Group}\text{number}-\text{valence}\text{electrons}\\ & =& 4-3\\ & =& 1\end{array}$

Thus, the formal charge on carbon atom in ${\text{CH}}_{\text{3}}$ molecule is $1$.

Conclusion

The non-hydrogen atom in ${\text{CH}}_{\text{3}}$ molecule is carbon atom that does not have a complete octet. The formal charge on carbon atom is found to be $1$.

Interpretation Introduction

(b)

Interpretation:

The non-hydrogen atom from the given species having a complete octet is to be stated. The formal charge on the atom is to be stated.

Concept introduction:

Chemical compounds contain two types of bonds. These are known as ionic and covalent bonds. In ionic bonds, the ions are held by the electrostatic interaction between them. In covalent bonds, the atoms are held together by the sharing of electrons. The formal charge is the charge on the constituent atoms in a molecule. It is calculated by using valence electrons of the atom.

Answer to Problem 1.22AP

The non-hydrogen atom in ${\text{:NH}}_{\text{3}}$ molecule is nitrogen atom that does have a complete octet. The formal charge on nitrogen atom is found to be $0$.

Explanation of Solution

The structure of ${\text{:NH}}_{\text{3}}$ molecule is shown in figure 2.

Figure 2

From the above figure, it is clear that number of electrons around nitrogen atom is $8$. Thus, it does have complete octet. The group number for nitrogen atom is $5$. The formal charge on atom is calculated by the formula given below as,

$\text{Formal}\text{charge}=\text{Group}\text{number}-\text{valence}\text{electrons}$

The valence electrons of nitrogen atom in the ${\text{:NH}}_{\text{3}}$ molecule is $5$. Substitute the values in above equation as follows.

$\begin{array}{rll}\text{Formal}\text{charge}& =& \text{Group}\text{number}-\text{valence}\text{electrons}\\ & =& 5-5\\ & =& 0\end{array}$

Thus, the formal charge on nitrogen atom in ${\text{:NH}}_{\text{3}}$ molecule is $0$.

Conclusion

The non-hydrogen atom in ${\text{:NH}}_{\text{3}}$ molecule is nitrogen atom that does have a complete octet. The formal charge on nitrogen atom is found to be $0$.

Interpretation Introduction

(c)

Interpretation:

The non-hydrogen atom from the given species having a complete octet is to be stated. The formal charge on the atom is to be stated.

Concept introduction:

Chemical compounds contain two types of bonds. These are known as ionic and covalent bonds. In ionic bonds, the ions are held by the electrostatic interaction between them. In covalent bonds, the atoms are held together by the sharing of electrons. The formal charge is the charge on the constituent atoms in a molecule. It is calculated by using valence electrons of the atom.

Answer to Problem 1.22AP

The non-hydrogen atom in ${\text{:CH}}_{\text{3}}$ molecule is carbon atom that does have a complete octet. The formal charge on carbon atom is found to be $-1$.

Explanation of Solution

The structure of ${\text{:CH}}_{\text{3}}$ molecule is shown in figure 3.

Figure 3

From the above figure, it is clear that number of electrons around carbon atom is $8$. Thus, it does have complete octet. The group number for carbon atom is $4$. The formal charge on atom is calculated by the formula given below as,

$\text{Formal}\text{charge}=\text{Group}\text{number}-\text{valence}\text{electrons}$

The valence electrons of carbon atom in the ${\text{:CH}}_{\text{3}}$ molecule is $5$. Substitute the values in above equation as follows.

$\begin{array}{rll}\text{Formal}\text{charge}& =& \text{Group}\text{number}-\text{valence}\text{electrons}\\ & =& 4-5\\ & =& -1\end{array}$

Thus, the formal charge on carbon atom in ${\text{:CH}}_{\text{3}}$ molecule is $-1$.

Conclusion

The non-hydrogen atom in ${\text{:CH}}_{\text{3}}$ molecule is carbon atom that does have a complete octet. The formal charge on carbon atom is found to be $-1$.

Interpretation Introduction

(d)

Interpretation:

The non-hydrogen atom from the given species having a complete octet is to be stated. The formal charge on the atom is to be stated.

Concept introduction:

Chemical compounds contain two types of bonds. These are known as ionic and covalent bonds. In ionic bonds, the ions are held by the electrostatic interaction between them. In covalent bonds, the atoms are held together by the sharing of electrons. The formal charge is the charge on the constituent atoms in a molecule. It is calculated by using valence electrons of the atom.

Answer to Problem 1.22AP

The non-hydrogen atom in ${\text{BH}}_{\text{3}}$ molecule is boron atom that does have a complete octet. The formal charge on boron atom is found to be $0$.

Explanation of Solution

The structure of ${\text{BH}}_{\text{3}}$ molecule is shown in figure 4.

Figure 4

From the above figure, it is clear that number of electrons around boron atom is $6$. Thus, it does not have complete octet. The group number for boron atom is $3$. The formal charge on atom is calculated by the formula given below as,

$\text{Formal}\text{charge}=\text{Group}\text{number}-\text{valence}\text{electrons}$

The valence electrons of boron atom in the ${\text{BH}}_{\text{3}}$ molecule is $3$. Substitute the values in above equation as follows.

$\begin{array}{rll}\text{Formal}\text{charge}& =& \text{Group}\text{number}-\text{valence}\text{electrons}\\ & =& \text{3}-3\\ & =& 0\end{array}$

Thus, the formal charge on boron atom in ${\text{BH}}_{\text{3}}$ molecule is $0$.

Conclusion

The non-hydrogen atom in ${\text{BH}}_{\text{3}}$ molecule is boron atom that does have a complete octet. The formal charge on boron atom is found to be $0$.

Interpretation Introduction

(e)

Interpretation:

The non-hydrogen atom from the given species having a complete octet is to be stated. The formal charge on the atom is to be stated.

Concept introduction:

Chemical compounds contain two types of bonds. These are known as ionic and covalent bonds. In ionic bonds, the ions are held by the electrostatic interaction between them. In covalent bonds, the atoms are held together by the sharing of electrons. The formal charge is the charge on the constituent atoms in a molecule. It is calculated by using valence electrons of the atom.

Answer to Problem 1.22AP

The non-hydrogen atom in $\stackrel{··}{\text{:I:}}$ is iodine atom that does not have a complete octet. The formal charge on iodine atom is found to be $1$.

Explanation of Solution

The structure of $\stackrel{··}{\text{:I:}}$ is shown in figure 5.

Figure 5

From the above figure, it is clear that number of electrons around iodine atom is $6$. Thus, it does not have complete octet. The group number for iodine atom is $7$. The formal charge on atom is calculated by the formula given below as,

$\text{Formal}\text{charge}=\text{Group}\text{number}-\text{valence}\text{electrons}$

The valence electrons of iodine atom in the $\stackrel{··}{\text{:I:}}$ is $6$. Substitute the values in above equation as follows.

$\begin{array}{rll}\text{Formal}\text{charge}& =& \text{Group}\text{number}-\text{valence}\text{electrons}\\ & =& 7-6\\ & =& 1\end{array}$

Thus, the formal charge on iodine atom in $\stackrel{··}{\text{:I:}}$ is $1$.

Conclusion

The non-hydrogen atom in $\stackrel{··}{\text{:I:}}$ is iodine atom that does not have a complete octet. The formal charge on iodine atom is found to be $1$.

Interpretation Introduction

(f)

Interpretation:

The non-hydrogen atom from the given species having a complete octet is to be stated. The formal charge on the atom is to be stated.

Concept introduction:

Chemical compounds contain two types of bonds. These are known as ionic and covalent bonds. In ionic bonds, the ions are held by the electrostatic interaction between them. In covalent bonds, the atoms are held together by the sharing of electrons. The formal charge is the charge on the constituent atoms in a molecule. It is calculated by using valence electrons of the atom.

Answer to Problem 1.22AP

The non-hydrogen atom in ${\text{BH}}_4$ molecule is boron atom that does have a complete octet. The formal charge on boron atom is found to be $-1$.

Explanation of Solution

The structure of ${\text{BH}}_4$ molecule is shown in figure 6.

Figure 6

From the above figure, it is clear that number of electrons around boron atom is $8$. Thus, it does have complete octet. The group number for boron atom is $3$. The formal charge on atom is calculated by the formula given below as,

$\text{Formal}\text{charge}=\text{Group}\text{number}-\text{valence}\text{electrons}$

The valence electrons of boron atom in the ${\text{BH}}_4$ molecule is $4$. Substitute the values in above equation as follows.

$\begin{array}{rllll}\text{Formal}\text{charge}& & =& & \text{Group}\text{number}-\text{valence}\text{electrons}\\ & & =& & 3-4\\ & & =& & -1\end{array}$

Thus, the formal charge on boron atom in ${\text{BH}}_4$ molecule is $-1$.

Conclusion

The non-hydrogen atom in ${\text{BH}}_4$ molecule is boron atom that does have a complete octet. The formal charge on boron atom is found to be $-1$.