Book cover for Chemistry

Chemistry

Catherine E. Housecroft, Edwin C. Constable

ISBN #9780273715450

4th Edition

995 Questions

Group icon
13,222 Students Helped

Homework Questions

Right arrow
Summary
Learning Objectives
Key Concepts
Example Problems
Explanations
Common Mistakes

Summary

This section provides a comprehensive exploration of the bonding in heteronuclear diatomic molecules. It covers methods to draw Lewis structures, contrasts between valence bond and molecular orbital theories, and discusses how electronegativity differences influence bond enthalpy and molecular polarity. Special attention is given to molecules like HF, LiF, LiH, and CO, and the discussion extends to isoelectronic species and various electronegativity scales, helping students understand the nuanced nature of chemical bonding.

Learning Objectives

1

-

2

2.

3

E

4

x

5

p

Key Concepts

CONCEPT

DEFINITION

Acyclic and cyclic alkanes

A discussion of both open?chain (acyclic) and ring (cyclic) saturated hydrocarbons, emphasizing their structural features, nomenclature, conformational behavior (including ring strain and conformation), and the processes used in their interconversion and synthesis.

Example Problems

Example 1

The normalized wavefunction for a bonding $\mathrm{MO}$ in a heteronuclear diatomic molecule AB is given by the equation: $$ \psi(\mathbf{M O})=\left(0.93 \times \psi_{\mathrm{A}}\right)+\left(0.37 \times \psi_{\mathrm{B}}\right) $$ What can you deduce about the relative values of $Z_{\text {eff }}$ for atoms $A$ and $B ?$

Example 2

Give resonance structure(s) for the hydroxide ion $[\mathrm{OH}]^{-} .$ What description of the bonding in this ion does valence bond theory give?

Example 3

Bearing in mind that $[\mathrm{OH}]^{-}$ is isoelectronic with HF, construct an approximate MO diagram to describe the bonding in $[\mathrm{OH}]^{-} .$ What is the bond order in $[\mathrm{OH}]^{-} ?$ Does the MO picture of the bonding differ from that obtained in the previous question using VB theory?

Example 4

Calculate the bond dissociation enthalpy of chlorine monofluoride, ClF, if the bond dissociation enthalpies of $\mathrm{F}_{2}$ and $\mathrm{Cl}_{2}$ are 159 and $242 \mathrm{kJ} \mathrm{mol}^{-1}$ respectively, $\chi^{\mathfrak{F}}(\mathbf{F})=4.0,$ and $\chi^{\mathbf{P}}(\mathbf{C l})=3.2$ $\left(1 \mathrm{eV}=96.5 \mathrm{kJ} \mathrm{mol}^{-1}\right) .$ Compare your answer with the experimental value.

Example 5

(a) Are equations 5.15 and 5.16 restricted to use in diatomic XY molecules? (b) Given that $D(\mathrm{O}-\mathrm{O})$ and $D(\mathrm{H}-\mathrm{H})$ are 146 and $436 \mathrm{kJ} \mathrm{mol}^{-1}$ respectively, estimate a bond enthalpy term for an O-H bond.
Scroll left
Scroll right

Step-by-Step Explanations

Scroll left
Scroll right

Common Mistakes

  • -
  • 2.
  • O
  • v
  • e