Book cover for Chemistry

Chemistry

Catherine E. Housecroft, Edwin C. Constable

ISBN #9780273715450

4th Edition

995 Questions

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13,222 Students Helped

Homework Questions

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Summary
Learning Objectives
Key Concepts
Example Problems
Explanations
Common Mistakes

Summary

This section explores Hydrogen alongside the s-block elements, highlighting their unique properties, electron configurations, and trends in reactivity. Key distinctions include Hydrogen's singular nature compared to the typically metallic character of alkali and alkaline earth metals. By mastering these concepts, students can predict and explain chemical behaviors of these elements, an essential skill in both academic and real-world chemical applications.

Learning Objectives

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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

An absorption in an IR spectrum of an organic compound comes at $3100 \mathrm{cm}^{-1}$ and is assigned to an $\mathrm{X}-\mathrm{H}$ bond where $\mathrm{X}=\mathrm{C}, \mathrm{O}$ or $\mathrm{N} .$ Determine the shift in this band upon deuteration of the $X-H$ bond for (a) $\mathrm{X}=^{12} \mathrm{C},$ (b) $\mathrm{X}=^{16} \mathrm{O}$ and (c) $\mathrm{X}=^{14} \mathrm{N}$

Example 2

Why are kinetic isotope effects useful for reactions involving $\mathrm{C}-\mathrm{H}$ bonds but are not likely to be of significant use in studying reactions involving $^{12} \mathrm{C}=\mathrm{O}$ and $^{13} \mathrm{C}=\mathrm{O}$ labelled compounds?

Example 3

Which of the following metal ions might be reduced to the respective metal by $\mathrm{H}_{2}:(\mathrm{a}) \mathrm{Cu}^{2+}$ (b) $\mathrm{Zn}^{2+} ;(\mathrm{c}) \mathrm{Fe}^{2+} ;(\mathrm{d}) \mathrm{Ni}^{2+} ;(\mathrm{e}) \mathrm{Mn}^{2+} ?$ Conversely, which of the following metals would react with dilute sulfuric acid to generate $\mathrm{H}_{2}:$ (a) $\mathrm{Mg} ;$ (b) Ag; (c) $\mathrm{Ca} ;$ (d) $\mathrm{Zn} ;$ (e) $\mathrm{Cr} ?$

Example 4

The standard enthalpies of formation (298 K) of methanol and octane are -239 and $-250 \mathrm{kJ} \mathrm{mol}^{-1}$. Determine the enthalpy change when a mole of each is fully combusted, and assess the relative merits of these compounds as fuels. $\left(\Delta_{f} H^{\circ}\right.$ $\left.\mathrm{CO}_{2}(\mathrm{g})=-394, \mathrm{H}_{2} \mathrm{O}(\mathrm{l})=-286 \mathrm{kJ} \mathrm{mol}^{-1} .\right)$

Example 5

In Section 21.5 we stated that "the tetrahydridoborate anion is kinetically stable towards hydrolysis'. What does this mean? How does kinetic stability in this case differ from thermodynamic stability? Suggest why the cobalt is present in the "cobalt-doped pellets of $\mathrm{Na}\left[\mathrm{BH}_{4}\right]$ ' mentioned in Section 21.5
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Step-by-Step Explanations

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Common Mistakes

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