Chapter 6, Problem 47QRT

(a)

Interpretation Introduction

Interpretation:

The bond type for each bond in ${\text{POF}}_{\text{3}}$ has to be determined using Lewis structure and a formal charge.

Concept Introduction:

Lewis structure is also known as Lewis dot diagrams or electron dot structures.  The bond between atoms and lone pairs of electrons that is present in the molecule.  Lewis structure represents each atom and their position in structure using the chemical symbol.  Excess electrons forms the lone pair are given by pair of dots, and are located next to the atom.

The formula for the formal charge can be written as

  $\text{Formal}\text{charge=}\text{Valence}\text{electrons-lone}\text{pair}\text{electrons}\text{-}\frac{\text{Bonding}\text{electrons}}{\text{2}}$

Explanation of Solution

The correct Lewis structure of the ${\text{POF}}_{\text{3}}$ can be drawn as,

Draw a chart:

  $\overline{\begin{array}{l}\text{O}\text{N}\text{Cl}\\ \text{P}\text{O}\text{F}\\ \overline{\underset{\_}{\begin{array}{l}\text{Valence}\text{electrons}56\text{7}\\ \text{Lone}\text{pair}\text{electrons}046\\ \text{Bonding}\text{electrons}1042\\ \text{Formal}\text{charge}0\text{0}0\end{array}}}\end{array}}$

The total number of valence electron is $32.$

The phosphorous atom has three single bonds and one double bond; both fluorine and oxygen have a one single bond.  All atoms in ${\text{POF}}_{\text{3}}$ has zero formal charge.

The bond between $\text{P-F}$ is single bond and the bond between $\text{P=O}$ is a double bond. 

(b)

Interpretation Introduction

Interpretation:

The bond type for each bond in ${\text{SOF}}_{\text{3}}$ has to be determined using Lewis structure and a formal charge.

Concept Introduction:

Refer part (a).

Explanation of Solution

The correct Lewis structure of the ${\text{SOF}}_{\text{3}}$ can be drawn as,

Draw a chart:

  $\overline{\begin{array}{l}S\text{O}\text{F}\\ \overline{\underset{\_}{\begin{array}{l}\text{Valence}\text{electrons}66\text{7}\\ \text{Lone}\text{pair}\text{electrons}046\\ \text{Bonding}\text{electrons}1242\\ \text{Formal}\text{charge}0\text{0}0\end{array}}}\end{array}}$

The total number of valence electron is $40.$

The sulfur atom has four single bonds and one double bond; all fluorine has a one single bond, oxygen has double bond.  All atoms in ${\text{SOF}}_{\text{3}}$ has zero formal charge.

The bond between $\text{S-F}$ is single bond and the bond between $\text{S=O}$ is a double bond.