Contents ap 6 Chapter 7 Equilibrium Chemistry 135 obtaining and Preparing Samples fo nalySIs 79 6A Reversible reactions and Chemical quilibria 136 7A The Importance of Sampling 180 ling plan 1 Chemistry 136 7B. 1 Where to Sample the Target 6C Manipulating Equilibrium Constants 138 6D Equilibrium Constants for Chemica 7B.2 What Type of Sample to Collect 185 Reactions 139 B3 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 6D.3 Complexation Reactions 144 7C Implementing the Sampling Plan 193 D 4 Oxidation-Reduction Reactions 14 7C.1 Solutions 193 E Le Chatelier'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 nterferents 201 Equilibria 153 E General Theory of separation 6F. 3 Ladder Diagrams for Oxidation-Reduction 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(IO3)2in 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 lon 6G.3 Systematic Approach to Solving Equilibrium of State 209 Problems 159 7F.5 Separations Based on a Partitioning Betwe 6G.4 pH of a Monoprotic Weak Acid 160 Phases 211 6G.5 pH of a Polyprotic Acid or Base 7G Liquid-Liquid Extractions 215 6G.6 Effect of Complexation on Solubilit 7G.1 Partition Coefficients and Distribution 6H Buffer Solutions 167 Ratio 6H. 1 Systematic Solution to Buffer G2 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 61 Activity Effects 171 7G.4 Liquid-Liquid Extractions Involving Metal 6] Two Final Thoughts About Equilibrium Chelators 221 Chemistry 175 7H Separation versus Preconcentration 223 6K Key Terms 17 71 Key Terms 224 6L Summary 175 6M Suggested Experiments 176 Suggested Experiments 225 6n Problems 176 Problems 226 60 Suggested Readings 178 7M Suggested Readings 230 6P References 178 7n References 231Contents v Chapter 7 Obtaining and Preparing Samples for Analysis 179 7A The Importance of Sampling 180 7B Designing a Sampling Plan 182 7B.1 Where to Sample the Target Population 182 7B.2 What Type of Sample to Collect 185 7B.3 How Much Sample to Collect 187 7B.4 How Many Samples to Collect 191 7B.5 Minimizing the Overall Variance 192 7C Implementing the Sampling Plan 193 7C.1 Solutions 193 7C.2 Gases 195 7C.3 Solids 196 7D Separating the Analyte from Interferents 201 7E General Theory of Separation Efficiency 202 7F Classifying Separation Techniques 205 7F.1 Separations Based on Size 205 7F.2 Separations Based on Mass or Density 206 7F.3 Separations Based on Complexation Reactions (Masking) 207 7F.4 Separations Based on a Change of State 209 7F.5 Separations Based on a Partitioning Between Phases 211 7G Liquid–Liquid Extractions 215 7G.1 Partition Coefficients and Distribution Ratios 216 7G.2 Liquid–Liquid Extraction with No Secondary Reactions 216 7G.3 Liquid–Liquid Extractions Involving Acid–Base Equilibria 219 7G.4 Liquid–Liquid Extractions Involving Metal Chelators 221 7H Separation versus Preconcentration 223 7I Key Terms 224 7J Summary 224 7K Suggested Experiments 225 7L Problems 226 7M Suggested Readings 230 7N References 231 Chapter 6 Equilibrium Chemistry 135 6A Reversible Reactions and Chemical Equilibria 136 6B Thermodynamics and Equilibrium Chemistry 136 6C Manipulating Equilibrium Constants 138 6D Equilibrium Constants for Chemical Reactions 139 6D.1 Precipitation Reactions 139 6D.2 Acid–Base Reactions 140 6D.3 Complexation Reactions 144 6D.4 Oxidation–Reduction Reactions 145 6E Le Châtelier’s Principle 148 6F Ladder Diagrams 150 6F.1 Ladder Diagrams for Acid–Base Equilibria 150 6F.2 Ladder Diagrams for Complexation Equilibria 153 6F.3 Ladder Diagrams for Oxidation–Reduction Equilibria 155 6G Solving Equilibrium Problems 156 6G.1 A Simple Problem: Solubility of Pb(IO3)2 in Water 156 6G.2 A More Complex Problem: The Common Ion Effect 157 6G.3 Systematic Approach to Solving Equilibrium Problems 159 6G.4 pH of a Monoprotic Weak Acid 160 6G.5 pH of a Polyprotic Acid or Base 163 6G.6 Effect of Complexation on Solubility 165 6H Buffer Solutions 167 6H.1 Systematic Solution to Buffer Problems 168 6H.2 Representing Buffer Solutions with Ladder Diagrams 170 6I Activity Effects 171 6J Two Final Thoughts About Equilibrium Chemistry 175 6K Key Terms 175 6L Summary 175 6M Suggested Experiments 176 6N Problems 176 6O Suggested Readings 178 6P References 178 1400-Fm 9/9/99 7:38 AM Page v