Chapter 5, Problem 5.76CHP

(a)

Interpretation Introduction

Interpretation:

The electron-dot structure for the molecule ${\text{F}}_{\text{3}}\text{S}-\text{S}-\text{F}$ and the geometry of every nonterminal atom in the molecule has to be determined.

Concept introduction:

Electron-dot structure: It is a diagram in which dots are placed around the chemical symbol of an element to show its valence electrons. It is also called as Lewis dot diagrams.

VSEPR theory:

• Using VSEPR theory, the exact geometry of a molecule can be obtained.
• In VSEPR, the geometry of the molecule is explained based on minimizing electrostatic repulsion between the molecules’ valence electrons around a central atom
• Bond angle is the angle between two bonds of a molecule and it is determined based on the electron-domain geometry.

  [Bond angles: tetrahedral = $\text{109}{\text{.5}}^{\text{o}}$, trigonal planar = ${\text{120}}^{\text{o}}$, T-shape = ${\text{90}}^{\text{o}}$]

Rules to predict the shapes of molecules by VSEPR model:

• Write electron-dot structure of the given molecule.
• Count the number of electron charge clouds surrounding the central atom.
• Determine the geometric arrangement of charge clouds surround the each atom and assume its charge clouds can be oriented in the space as far away from one to another as possible.

(b)

Interpretation Introduction

Interpretation:

The electron-dot structure for the molecule ${\text{CH}}_{\text{3}}-\text{C}\equiv {\text{CCO}}_{\text{2}}{}^{-}$ and the geometry of every nonterminal atom in the molecule has to be determined.

Concept introduction:

Electron-dot structure: It is a diagram in which dots are placed around the chemical symbol of an element to show its valence electrons. It is also called as lewis dot diagrams.

VSEPR theory:

• Using VSEPR theory, the exact geometry of a molecule can be obtained.
• In VSEPR, the geometry of the molecule is explained based on minimizing electrostatic repulsion between the molecules’ valence electrons around a central atom
• Bond angle is the angle between two bonds of a molecule and it is determined based on the electron-domain geometry.

  [Bond angles: tetrahedral = $\text{109}{\text{.5}}^{\text{o}}$, trigonal planar = ${\text{120}}^{\text{o}}$, T-shape = ${\text{90}}^{\text{o}}$]

Rules to predict the shapes of molecules by VSEPR model:

• Write electron-dot structure of the given molecule.
• Count the number of electron charge clouds surrounding the central atom.
• Determine the geometric arrangement of charge clouds surround the each atom and assume its charge clouds can be oriented in the space as far away from one to another as possible.