Page 6 - Modern Analytical Chemistry

1400-Fm 9/9/99 7:38 AM Page v

Contents v
Chapter 6 Chapter 7

Equilibrium Chemistry 135 Obtaining and Preparing Samples
for Analysis 179
6A Reversible Reactions and Chemical
Equilibria 136 7A The Importance of Sampling 180
6B Thermodynamics and Equilibrium 7B Designing a Sampling Plan 182
Chemistry 136 7B.1 Where to Sample the Target
6C Manipulating Equilibrium Constants 138 Population 182
6D Equilibrium Constants for Chemical 7B.2 What Type of Sample to Collect 185
Reactions 139 7B.3 How Much Sample to Collect 187
6D.1 Precipitation Reactions 139 7B.4 How Many Samples to Collect 191
6D.2 Acid–Base Reactions 140 7B.5 Minimizing the Overall Variance 192
6D.3 Complexation Reactions 144 7C Implementing the Sampling Plan 193
6D.4 Oxidation–Reduction Reactions 145 7C.1 Solutions 193
6E Le Châtelier’s Principle 148 7C.2 Gases 195
6F Ladder Diagrams 150 7C.3 Solids 196
6F.1 Ladder Diagrams for Acid–Base Equilibria 150 7D Separating the Analyte from
6F.2 Ladder Diagrams for Complexation Interferents 201
Equilibria 153 7E General Theory of Separation
6F.3 Ladder Diagrams for Oxidation–Reduction Efficiency 202
Equilibria 155 7F Classifying Separation Techniques 205
6G Solving Equilibrium Problems 156 7F.1 Separations Based on Size 205
6G.1 A Simple Problem: Solubility of Pb(IO 3 ) 2 in 7F.2 Separations Based on Mass or Density 206
Water 156
7F.3 Separations Based on Complexation
6G.2 A More Complex Problem: The Common Ion Reactions (Masking) 207
Effect 157 7F.4 Separations Based on a Change
6G.3 Systematic Approach to Solving Equilibrium of State 209
Problems 159 7F.5 Separations Based on a Partitioning Between
6G.4 pH of a Monoprotic Weak Acid 160 Phases 211
6G.5 pH of a Polyprotic Acid or Base 163 7G Liquid–Liquid Extractions 215
6G.6 Effect of Complexation on Solubility 165 7G.1 Partition Coefficients and Distribution
6H Buffer Solutions 167 Ratios 216
6H.1 Systematic Solution to Buffer 7G.2 Liquid–Liquid Extraction with No Secondary
Problems 168 Reactions 216
6H.2 Representing Buffer Solutions with 7G.3 Liquid–Liquid Extractions Involving
Ladder Diagrams 170 Acid–Base Equilibria 219
6I Activity Effects 171 7G.4 Liquid–Liquid Extractions Involving Metal
6J Two Final Thoughts About Equilibrium Chelators 221
Chemistry 175 7H Separation versus Preconcentration 223
6K Key Terms 175 7I Key Terms 224
6L Summary 175 7J Summary 224
6M Suggested Experiments 176 7K Suggested Experiments 225
6N Problems 176 7L Problems 226
6O Suggested Readings 178 7M Suggested Readings 230
6P References 178 7N References 231