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