Chemistry and Chemical Reactivity

John C. Kotz, Paul M. Treichel, John R. Townsend

ISBN #9780840048288

8th Edition

2,165 Questions

24,952 Students Helped

Homework Questions

Summary

Learning Objectives

Key Concepts

Example Problems

Explanations

Common Mistakes

Summary

This section integrates several core topics of aqueous equilibria including the solubility product constant (Ksp), the reaction quotient (Q), and the effects of common ions on solubility. It further explores how complex ion formation—quantified by high formation constants (Kf)—can substantially enhance the solubility of sparingly soluble salts, an effect useful in processes such as gold extraction. The chapter also connects these chemical equilibrium principles to thermodynamic considerations, emphasizing that while hydrogen fuel production holds promise, energy losses dictated by the second law of thermodynamics limit the efficiency of such methods. Understanding these combined effects is essential for solving practical problems in chemical reactivity and industrial applications.

Learning Objectives

Key Concepts

CONCEPT

DEFINITION

Brønsted–Lowry and Lewis definitions

A study of acid–base concepts encompassing both the Brønsted–Lowry and Lewis definitions. This topic explains how to write balanced acid–base reactions, analyze equilibria using ICE tables, and understand molecular influences (such as bond strength and resonance) on acid strength.

Example Problems

Example 1

Does the $\mathrm{pH}$ of the solution increase, decrease, or stay the same when you (a) add solid ammonium chloride to a dilute aqueous solution of $\mathrm{NH}_{3} ?$ (b) add solid sodium acetate to a dilute aqueous solution of acetic acid? (c) add solid NaCl to a dilute aqueous solution of NaOH?

Example 2

Does the pH of the solution increase, decrease, or stay the same when you (a) add solid sodium oxalate, $\mathrm{Na}_{2} \mathrm{C}_{2} \mathrm{O}_{4},$ to $50.0 \mathrm{mL}$ of $0.015 \mathrm{M}$ oxalic acid, $\mathrm{H}_{2} \mathrm{C}_{2} \mathrm{O}_{4} ?$ (b) add solid ammonium chloride to 75 mL of $0.016 \mathrm{M}$ HCl? (c) add $20.0 \mathrm{g}$ of $\mathrm{NaCl}$ to $1.0 \mathrm{L}$ of $0.10 \mathrm{M}$ sodium acetate, $\mathrm{NaCH}_{3} \mathrm{CO}_{2} ?$

Example 3

What is the pH of a solution that consists of $0.20 \mathrm{M}$ ammonia, $\mathrm{NH}_{3},$ and $0.20 \mathrm{M}$ ammonium chloride, $\mathrm{NH}_{4} \mathrm{Cl} ?$

Example 4

What is the pH of $0.15 \mathrm{M}$ acetic acid to which $1.56 \mathrm{g}$ of sodium acetate, $\mathrm{NaCH}_{3} \mathrm{CO}_{2},$ has been added?

Example 5

What is the pH of the solution that results from adding $30.0 \mathrm{mL}$ of $0.015 \mathrm{M} \mathrm{KOH}$ to $50.0 \mathrm{mL}$ of $0.015 \mathrm{M}$ benzoic acid?