Chapter 14, Problem 14.34P

(a)

Interpretation Introduction

Interpretation:

The electron deficiency has to be explained.

Concept Introduction:

Octet rule:

It tells about the stability of inorganic compounds, which contains the main group elements.

In a compound, the central metal contains $8$ electrons in its outermost shell is most stable.

Explanation of Solution

According to octet rule, the outer most shell of central metal contains 8 electrons is the most stable. Some compounds contains lesser than this so these central metal ion are know as electron deficiency atom or ion.

For example,

Boron trifluoride $B{F}_3$

The electronic configuration $B{F}_3$ is,

    $\begin{array}{l}B\boxed{1S^2}\boxed{\boxed{2s^2}\boxed{2p^1}}\\ shellKl\\ B{F}_3\boxed{1S^2}\boxed{\boxed{2s^2}\boxed{2p^4}}\end{array}$

Boron contains $6$ electro in boron trifluoride, it required 2 electrons to attain the noble gas electronic configuration therefore, $B{F}_3$ is electron deficient molecule.

(b)

Interpretation Introduction

Interpretation:

The reactions that illustrate electron deficiency behavior has to be given.

Concept Introduction:

Octet rule:

It tells about the stability of inorganic compounds, which contains the main group elements.

In a compound, the central metal contains $8$ electrons in its outermost shell is most stable.

Explanation of Solution

According to octet rule, the outer most shell of central metal contains 8 electrons is the most stable. Some compounds contains lesser than this so these central metal ion are known as electron deficiency atom or ion.

For example,

Boron trifluoride $B{F}_3$

The electronic configuration $B{F}_3$ is,

    $\begin{array}{l}B\boxed{1S^2}\boxed{\boxed{2s^2}\boxed{2p^1}}\\ shellKl\\ B{F}_3\boxed{1S^2}\boxed{\boxed{2s^2}\boxed{2p^4}}\end{array}$

Boron contains $6$ electro in boron trifluoride, it required 2 electrons to attain the noble gas electronic configuration therefore, $B{F}_3$ is electron deficient molecule.

    $\begin{array}{l}{\text{BF}}_{\text{3(g)}}{\text{ + NH}}_{\text{3(g)}}\stackrel{}{\to }{\text{BF}}_{\text{3}}{\text{-NH}}_{\text{3}}{}_{\text{(g)}}\\ \\ {\text{B(OH)}}_{\text{3(aq) }}{\text{+ OH}}^{-}{}_{\text{(aq)}}\stackrel{}{\to }{\text{B(OH)}}_{\text{3(aq)}}\end{array}$

$B{F}_3$ is an electron deficient molecule, it react with $N{H}_3$ form a complex and $B{\left(OH\right)}_3$ react with $O{H}^{-}$ ion to give $B{\left(OH\right)}_4{}^{-}$, these reaction shows the lone pair of  $N{H}_3$ and negative charge of hydroxide are used to fulfil the octet rule, therefore, the Boron compounds are electron deficient compounds.