Chemistry

Catherine E. Housecroft, Edwin C. Constable

ISBN #9780273715450

4th Edition

995 Questions

13,222 Students Helped

Homework Questions

Summary

Learning Objectives

Key Concepts

Example Problems

Explanations

Common Mistakes

Summary

This section explores the fundamental concepts of ions, beginning with the visualization provided by electron density maps and moving through the energetics of ion formation such as ionization energy and electron affinity. It further delves into the nature of electrostatic interactions that lead to the formation of ionic lattices, culminating in a detailed understanding of the sodium chloride (rock salt) structure. The interplay of these factors is essential for grasping the behavior, properties, and applications of ionic compounds.

Learning Objectives

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

With reference to the oxygen atom, explain what you understand by the (a) first ionization energy, (b) second ionization energy, (c) first electron affinity, (d) second electron affinity and (e) enthalpy change associated with the attachment of an electron.

Example 2

The first five ionization energies of a gaseous atom $X$ are 589,1148,4911,6494 and $8153 \mathrm{kJ} \mathrm{mol}^{-1} .$ To what group is this element likely to belong?

Example 3

The first ionization energies of oxygen $(Z=8),$ fluorine $(Z=9),$ neon $(Z=10)$ and sodium $(Z=11)$ are 1312,1681,2080 and $495 \mathrm{kJ} \mathrm{mol}^{-1}$ respectively. Rationalize the trend in these values in terms of the electronic structures of these elements.

Example 4

Calculate the enthalpy change that accompanies the process: $$\frac{1}{2} \mathrm{Li}_{2}(\mathrm{g}) \rightarrow \mathrm{Li}^{+}(\mathrm{g})+\mathrm{e}^{-}$$ given that the bond enthalpy for dilithium is $110 \mathrm{kJ} \mathrm{mol}^{-1}$ and $I E_{1}$ for lithium is $520 \mathrm{kJ} \mathrm{mol}^{-1}.$

Example 5

Calculate the enthalpy change that accompanies the reaction: $$\frac{1}{2} \mathrm{Li}_{2}(\mathrm{g})+\mathrm{e}^{-}--\mathrm{Li}^{-}(\mathrm{g})$$ given that the bond enthalpy for $\mathrm{Li}_{2}$ is $110 \mathrm{kJ} \mathrm{mol}^{-1}$ and $E A_{1}$ for lithium is $60 \mathrm{kJ} \mathrm{mol}^{-1}$.