Chapter 8, Problem 5STP

Interpretation Introduction

Interpretation:

The Lewis structure for silicon disulfide is to be predicted.

Concept introduction:

The strategy for drawing Lewis structure is mention below.

• Calculate the number of valence electrons present in the molecule.
• Calculate the electron pairs by diving number of valence electrons by 2.
• Determine the bond pairs.
• Determine the lone pairs.
• Check whether the central atom satisfies octet rule.

Answer to Problem 5STP

The Lewis structure for silicon disulfide is shown below.

Therefore, option (B) is the correct option.

Explanation of Solution

Reason for correct option: The valence electron present in silicon disulfide $\left({\text{SiS}}_{\text{2}}\right)$ is the sum of the valence electron present in silicon $\left(\text{Si}\right)$ and valence present in two sulfur $\left(\text{S}\right)$ atoms. The number of valence electron present in silicon $\left(\text{Si}\right)$ atom is four. The number of valence electron present in sulfur $\left(\text{S}\right)$ is six. The number of valence electron present in silicon disulfide $\left({\text{SiS}}_{\text{2}}\right)$ is calculated as shown below.

$\begin{array}{c}\text{No}\text{.}\text{of}\text{valence}\text{electron}\text{in}{\text{SiS}}_{\text{2}}=\text{Si}+\text{2S}\\ =4{\text{e}}^{-}+2\times 6{\text{e}}^{-}\\ =16{\text{e}}^{-}\end{array}$

The number of electron pairs is calculated as shown below.

$\begin{array}{c}\text{No}\text{.}\text{of}\text{electron}\text{pairs}=\frac{16{\text{e}}^{-}}{2}\\ =8{\text{e}}^{-}\end{array}$

Among eight electron pairs, four electron pairs are involved in bonding and the remaining four electron pairs are present as lone pairs.

The Lewis structure for silicon disulfide is shown below.

Therefore, option (B) is the correct option.

Conclusion

Reason for incorrect option: The Lewis structure for silicon disulfide $\left({\text{SiS}}_{\text{2}}\right)$ does not corresponds to the given structure. So, A is incorrect option.

The Lewis structure for silicon disulfide $\left({\text{SiS}}_{\text{2}}\right)$ does not corresponds to the given structure. So, C is incorrect option.

The Lewis structure for silicon disulfide $\left({\text{SiS}}_{\text{2}}\right)$ does not corresponds to the given structure. So, D is incorrect option.