Chemistry. A Student's Practice Book. Pyskowice

Chemistry. A Student's Practice Book. Spis treści Table of Content Preface .................................................................................................. 7 Introduction: Safety in the Laboratory........................................................ 9 A – General Safety Rules ................................................................................. 9 B – How to Use a Bunsen Burner Safely ....................................................... 10 1. Chemical Reactions of Electrolytes in Aqueous Solutions 1.1. Dissociation Reactions ........................................................................ 15 1.1.1. Dissociation of Acids ................................................................ 15 1.1.2. Dissociation of Hydroxides ...................................................... 15 1.1.3. Dissociation of Salts ................................................................. 16 1.1.4. Dissociation of Water ................................................................ 16 1.2. Neutralisation Reactions ..................................................................... 16 1.3. Hydrolysis Reactions .......................................................................... 18 1.4. Precipitation Reactions ....................................................................... 19 1.5. Amphoteric Hydroxides Reactions with Strong Acids or Bases ......... 21 2. Reduction – Oxidation (Redox) Reactions 2.1. Redox Reactions.................................................................................. 23 2.2. Oxidation Number (State) ................................................................... 23 2.3. Manganate(VII) – Permanganate – in Redox Reactions ..................... 24 2.4. Balancing Redox Reaction Equations ................................................. 24 3. Analysis of Cations ................................................................................... 27 4. Analysis of Anions .................................................................................... 31 5. Introduction to Quantitative Analysis (Fundamentals) 5.1. Quantitative Analysis Definition. Divisions ....................................... 39 5.2. Laboratory Glassware ......................................................................... 40 5.2.1. Volumetric Flask ...................................................................... 41 5.2.2. Pipette ....................................................................................... 41 5.2.3. Burette ...................................................................................... 41 5.2.4. Scales ........................................................................................ 42 5.3. Basic Definitions and Procedures ....................................................... 42 6. Complexometry........................................................................................ 47 7. Manganometry.......................................................................................... 53 8. Acid-Base Titration .................................................................................. 59 CHEMISTRY A STUDENT’S PRACTICE BOOK 9. Recrystallisation of Organic Compounds 9.1. Process Fundamentals ..................................................................... 73 9.2. Choosing the Appropriate Solvent .................................................. 74 9.3. General Steps .................................................................................. 75 9.4. Heating the Suspension .................................................................. 76 9.5. Use of Decolourising Carbon ......................................................... 77 9.6. Cooling the Solution ....................................................................... 77 9.7. Filtering and Drying the Product .................................................... 77 9.8. Melting Point as the Criterion of Purity ......................................... 78 9.9. Percent Recovery ............................................................................ 78 10. Distillation 10.1. Distillation Fundamentals ............................................................... 81 10.2. Simple Distillation .......................................................................... 82 10.3. Fractional Distillation ..................................................................... 85 10.4. Vacuum Distillation ........................................................................ 86 10.5. Steam Distillation ........................................................................... 88 10.6. Hydrodistillation ............................................................................. 89 11. Isolation of Essential Oils from Biological Samples by Hydrodistillation .............................................................................. 93 12. Extraction .............................................................................................. 97 12.1. Extraction Fundamentals ............................................................... 97 12.2. Liquid-Liquid Extraction ............................................................... 97 12.2.1. Choosing a Solvent System ............................................... 99 12.2.2. Identifying the Layers ........................................................ 99 12.2.3. Separating the Layers ....................................................... 100 12.2.4. Drying Agents (Desiccants) ............................................. 100 12.2.5. Extraction of Essential Oils from Distillates ................... 102 12.2.6. Isolation of Lycopene from Tomato Paste ....................... 103 12.3. Acid-Base Extraction ................................................................... 104 12.3.1. Separation of Benzoic Acid and Toluene ......................... 105 12.4. Solid-Liquid Extraction (Leaching) ............................................ 106 12.4.1. Isolation of Sunflower Oil from Sunflower Seeds ........... 106 12.4.2. Isolation of Caffeine from Tea Leaves ............................. 107 13. Chromatography 13.1. General Principles .........................................................................111 13.2. Chromatographic Techniques ....................................................... 112 13.2.1. Column Chromatography .................................................. 112 13.2.2. Thin Layer Chromatography (TLC) ................................. 113 Table of Content 13.3. Analysis of Nitroaniline Isomers by Thin Layer Chromatography .......................................................................... 118 13.4. Analysis of Green Pigments in Plants ......................................... 119 14. Qualitative Analysis of Organic Compounds 14.1. Introduction to Qualitative Analysis ........................................... 121 14.2. Determination of Solubility Group ............................................. 121 14.3. Chemical (Classification) Tests ................................................... 124 15. Organic Syntheses 15.1. Introduction to Organic Synthesis ............................................... 139 15.2. Synthesis of Aspirin (Acetylsalicylic Acid) ................................ 140 15.3. Synthesis of n-Butyl Acetate ....................................................... 140 15.4. Synthesis of Dibenzylideneacetone ............................................. 141 15.5. Synthesis of Methyl m-Nitrobenzoate ......................................... 142 15.6. Synthesis of para-Red ................................................................. 143 15.7. Synthesis of Soap ........................................................................ 145 16. Calculation Problems 16.1. Concentration .............................................................................. 147 16.2. Complexometry ........................................................................... 150 16.3. Manganometry ............................................................................. 151 16.4. pH ................................................................................................ 152 16.5. Acid-Base Titration ...................................................................... 154 16.6. Recrystallisation .......................................................................... 155 16.7. Extraction .................................................................................... 156 16.8. Reaction Yield ............................................................................. 156 References .................................................................................................. 159 Appendix ................................................................................................... 160 Answers to Calculation Problems ........................................................... 165