Contents. Introduction. Concentrations of Solutions. Part I THEORETICAL ASPECTS CHAPTER Qualitative Analysis... 6 CHAPTER 2. Preface...

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1 Contents Preface... (v) Part I THEORETICAL ASPECTS CHAPTER 1 Introduction 1.1 Two Major Divisions of Analytical Chemistry Qualitative Analysis Quantitative Analysis Common Methods in Quantitative Analysis Gravimetry Electrogravimetry Gasometry Titrimetry/Volumetry Turbidimetry and Nephelometry Colorimetry and Spectrophotometry Electrochemical Methods Chromatographic Methods Radioactive Methods Working Out Calculations in Quantitative Analysis CHAPTER 2 Concentrations of Solutions 2.1 Solution Concentration of a Solution Expressing Concentrations of Solutions Per Cent Parts per Million (vii)

2 2.3.3 Parts per Billion Mole Mole Fraction Molarity (M) Formality (F) Molality (m) Normality (N) Equivalent and Equivalent Weight Equivalent Weight of a Substance May Vary Due to Different Kinds of Reactions For Acids and Bases, Due to Varying Number of Protons Released or Neutralized For Redox Agents, Due to Varying Number of Electrons Exchanged Interconversion of Major Concentration Terms Normality to Other Forms Molarity to Other Forms Molarity to Molality Standard Solution and Standardisation Primary Standard Substance Characteristics of a Primary Standard Substance Secondary Standard Substance Primary and Secondary Standard Solutions Practical Considerations for Standardisation based on Titrimetry Working Out Calculations on Concentrations of Solutions, Equivalent Weight and Normality, Molarity and Molality of Solutions CHAPTER 3 Fundamentals of Analytical Chemistry 3.1 Reversible and Irreversible Reactions Law of Mass Action (viii)

3 3.3 Acids and Bases Arrhenius Theory of Acids and Bases Lowry Bronsted Theory of Acids and Bases Lewis Theory of Acids and Bases Summary of the Concept of Acids and Bases Conjugate Acid and Conjugate Base Strong and Weak Electrolytes Degree of Dissociation of Weak Electrolytes Dissociation Constants of Weak Acids pk a Ostwald s Dilution Law Solubility Product Difference between Solubility Product and Ionic Product Solubility of Sparingly Soluble Salts in Relation to their Solubility Product For Salts of the Type AB For Salts of the Type A 2 B and AB For Salts of the Type AB 3 and A 3 B For Salts of the Type A 3 B For Salts of the Type A x B y Precipitation of Sparingly Soluble Salts Solubility Product and Common Ion Effect Application of Common Ion Effects Effect of Diverse Ions on the Solubility of Salts Complex Ions Ionic Product of Water The Basis for ph Scale ph of Strong and Weak Acids and Bases Buffers Buffers as ph Stabilisers Types of Buffers Mechanism of Buffer Action Buffer Capacity ph Range of Buffers Buffer Concentration (ix)

4 Uses of Buffers in Analytical Chemistry Significance of Buffers in Biological Systems Henderson Hasselbalch Equation Derivation of Henderson Hasselbalch Equation Applications of Henderson Hasselbalch Equation Hydrolysis of Salts Salts and their Hydrolysis Salts of Strong Acids and Strong Bases Salts of Strong Acids and Weak Bases Salts of Weak Acids and Strong Bases Salts of Weak Acids and Weak Bases Sum Up of the Hydrolysis of Salts Hydrolysis Constant of Salts Hydrolysis Constants and the Degree of Hydrolysis of Salts Oxidation Reduction Reactions Oxidation and Reduction Oxidation Reduction Oxidizing Agent Reducing Agent Oxidations and Reductions Occur Simultaneously Oxidizing and Reducing Agents Produce a New Reducing and Oxidizing Agents Oxidation Reduction Reactions Expressed in Ionic Forms Redox Potential and the Two Component Half Reactions of a Redox Reaction Oxidation State and Oxidation Number Rules for Assigning Oxidation Number of an Atom in a Redox Reaction Calculating Oxidation Number of an Atom in a Molecule Unique Cases of Deriving Oxidation Number Identifying the Oxidizing and Reducing Agent based on Oxidation Number (x)

5 3.27 Balancing Oxidation Reduction Reactions Oxidation Number Method Ion-Electron Method Working Out Calculations on ph, pk a, pk b, Degree of Dissociation, Solubility and Precipitation of Salts, Solubility Product, Preparation and ph of Prepared Buffers CHAPTER 4 Titrimetric Analysis 4.1 Essentials of Titrimetric Analysis Prerequisites for the Reaction Between Titrant and Titrand Different Kinds of Titrimetry Acid Base Titrimetry Oxidation Reduction Titrimetry Precipitation Titrimetry Complexometric Titrimetry Indicators in Titrations Salient Characteristics of an Indicator Different Kinds of Indicators CHAPTER 5 Acid Base Titrimetry 5.1 Acid Base Titration Indicators Criteria for Selecting Indicators in Acid Base Titrations Strong Acid Strong Base Titrations Weak Acid Strong Base Titrations Weak Base Strong Acid Titrations Weak Acid Weak Base Titrations Weak Acid Anion Strong Base Titrations Protonated Weak Base Cation Strong Base Titrations Polyprotic Acid Strong Base Titrations (xi)

6 5.3 Major Classes of Acid Base Indicators Pthaleins Sulfonpthaleins Azos Mixed and Screened Indicators Mixed Indicators Screened Indicators Acid Base Titration Curves Strong Acid Strong Base Titration Curve Weak Acid Strong Base Titration Curve Weak Base Strong Acid Titration Curve Weak Acid Weak Base Titration Curve Titration of Polybasic Acids Indicators for Neutralization of Na 2 CO 3 by Strong Acid CHAPTER 6 Oxidation Reduction Titrimetry 6.1 Common Oxidizing and Reducing Agents Potassium permanganate (KMnO 4 ) Potassium dichromate (K 2 Cr 2 O 7 ) Iodine (I 2 ) Ferrous ammonium sulfate Cerium ammonium nitrate Major Types of Oxidation Reduction Titrimetry Permanganometry Dichromatometry Iodimetry Iodometry Theory of Oxidation Reduction Titrimetry Transfer of Electrons in Oxidation Reduction Reactions Half-Cell Potentials of Oxidation Reduction Reactions Writing + Sign of Potential Difference (xii)

7 6.3.4 Electrode Potential and Nernst Equation Measurement of Half-Cell Potential Concentration Cells Reduction Potential of Galvanic Cells Two Half Cell Combined Half-Cells of Metal Electrodes and Oxidizing and Reducing Agents Concentrations of Oxidising and Reducing Agents and their Oxidation Reduction Potential Redox Potentials and Equilibrium Constants of Oxidation Reduction Reactions Formal Potential Titration Curves of Oxidation Reduction Reaction Titrations Indicators in Oxidation Reduction Titrations Titrants Themselves Serve as Indicators Indicators other than Redox Indicators Redox Indicators Redox Indicators in Frequent Use Phenanthroline (Ferroin) Diphenylamine Starch Methylene Blue CHAPTER 7 Precipitation Titrimetry 7.1 Prerequisites of Precipitation Titrimetry Titration Curves of Precipitation Titrations Precipitation Titration Indicators Indicator Forms a Coloured Precipitate Indicator Forms a Soluble Coloured Substance Indicator Gets Adsorbed over Precipitate Surface Commonly used Adsorption Indicators (xiii)

8 CHAPTER 8 Complexometric Titrimetry 8.1 Essentials of Complexometric Titrations Comlexometric Titrations Titrations Involving Monodentate Ligands Titrations Involving Polydentate Ligands Ethylenediaminetetraacetic Acid (EDTA) General Aspects EDTA as a Weak Acid EDTA Disodium Salt Complexes of EDTA with Metal Ions ph Factor for the Formation of Metal Ion-EDTA Complexes Stability of the Metal Ion-EDTA Complexes Effect of ph on the Conditional Formation Constant (K/f) More than One Complexing Agent and Altered Conditional Formation Constant (K/f) Titration Curves of Metal Ion-EDTA Complexometric Reactions Other Polydentate Ligands EGTA NTA (or NITA) DCTA (or DCYTA or CDTA) TTHA TETA DTPA Types of Complexometric Titrations Direct Titration Indirect Titration Back Titration Displacement Titration Masking and Demasking Agents Added Titrations Alkali Titration Other Methods (xiv)

9 8.8 Complexometric Titration Indicators ph Colour of Metallochromic Indicators Determining Indicator Error Postequivalence Rise in the Concentration of the Free Indicator Metal Ion-Complexing Agent Titrations without Metallochromic Indicator Complexometric Titration Indicators in Wide Use Murexide Calcon Patton and Reeder s Indicator Eriochrome Black T Calmagite Xylenol Orange Zincon Pyrocatechol Violet Complexometric Titration Indicators of Minor Use Redox Indicators in Complexometric Titrations Diphenylbezidine Variamine Blue B Screening Effect of Complexometric Titrations Indicators CHAPTER 9 Part II STANDARD SOLUTIONS Primary and Secondary Standard Solutions 9.1 Standard Solution Primary Standard Substances Primary Standard Solution Secondary Standard Solution (xv)

10 CHAPTER 10 Preparation of Standard Solutions 10.1 Standard Hydrochloric Acid Solution Standardisation Against Na 2 CO Standardisation Against Na 2 B 4 O Standardisation by Argentimetric Method Standardisation by Iodometric Method Standardisation by Potentiometry Standard Sulfuric Acid Solution Standardisation Against Na 2 CO Standard Nitric Acid Solution Standardisation Against Sodium carbonate Standard Acetic Acid Solution Standardisation Against NaOH Standard Sodium hydroxide Solution Standardisation Against Potassium hydrogen pthalate Standard potassium permanganate Solution Standardisation Against Na 2 C 2 O Standardisation of Against As 2 O Standardisation Against Metallic Iron Standard Sodium thiosulfate Solution Standardisation Against K 2 Cr 2 O Standardisation Against KIO Standard Iodine Solution Standardisation Against As 2 O Standardisation Against Na 2 S 2 O Standard EDTA Solution Standardisation Against Ca 2+ Solution Standard Silver nitrate Solution Standardisation Against Standard Chloride Solution using Soluble C r O 2 4 as the Indicator Standardisation Against Standard Chloride Solution using an Adsorption Indicator (xvi)

11 10.11 Standard Ammonium and Potassium Thiocyanate Solution Standardisation Against AgNO Standard Bromine Solution Standardisation Against Na 2 S 2 O Standard Ferrous Sulfate Solution Standardisation Against K 2 Cr 2 O Standard Potassium Ferrocyanide Solution Standardisation Against Zinc Solution Standard Stock Solutions of Important Metal and Nonmetal Ions Aluminium Ammonium Antimony Arsenic Barium Borate Cadmium Calcium Carbonate Chromium Cobalt Copper Iron Lead Magnesium Manganese Mercury Molybdenum Molybdate Nickel Nitrate Potassium Phosphate Silicon Silver Sodium (xvii)

12 CHAPTER Sulfate Tin Zinc Part III SPECTROPHOTOMETRY Colorimetry and UV-Visible Absorption Spectrophotometry 11.1 Electromagnetic Radiation Theory of Colorimetry and Absorption Spectrophotometry Deviations from Beer s Law Real Deviations Chemical Deviations Instrumental Deviations Application of Beer-Lambert Law Absorption Spectrum and Absorption Maxima (λ max ) Calibration Curve Instrumentation - Component Parts of a Colorimeter/Absorption Spectrophotometer Sources of Radiation Wavelength Selectors Sample Holders/Absorption Cells/Cuvetts Detectors Display Device/Read Out Modules Commercial Instruments Colour Comparators Filter Photometers Single Beam Spectrophotometers Double Beam Spectrophotometers Minor Variations in Instrumentation Split Beam Spectrophotometers Diode Array Optics (xviii)

13 CHAPTER 12 Flame Photometry 12.1 Principle of Flame Photometry Low Population of the Excited Atoms Limited Application of Flame Photometry Instrumentation Atomizer and Burner Monochromator Detector Display Device Advantages and Limitations of Flame Photometry Determination by Flame Photometry Preparation of Sample Solutions Preparation of the Standard Solutions Calibration of the Instrument Determination in Samples CHAPTER 13 Atomic Absorption Spectrophotometry 13.1 Principle of Atomic Absorption Spectrophotometry Instrumentation Source of Radiation Atomizer Optical System Detector Display Device Single and Double Beam Atomic Absorption Spectrophotometer Single Beam Absorption Spectrophotometer Double Beam Absorption Spectrophotometer Interferences in Atomic Absorption Spectrophotometry Chemical Interference Ionization Interference (xix)

14 Spectral Interference Emission Interference Matrix Interference Background Absorption Interference Sample Preparation Dry Ashing Wet Oxidation Fusion Pressure Dissolution Microwave Oven Digestion Specific Methods of Sample Preparation Calibration of the Instrument Part IV SOIL ANALYSIS CHAPTER 14 Soil Sampling 14.1 Process of Collection of Soil Samples Materials Required Depth of Soil Sampling Method of Soil Sampling Time for Collection of Soil Samples Places, Sites and Spots for Collection of Soil Samples Selecting the Spots for Drawing Soil Samples Method of Drawing Soil Samples Quartering Process of Collected Soil Samples Filling in an Information Sheet/Card Processing of Collected Soil Samples in the Laboratory Analysis Physical Characteristics Physico-Chemical and Chemical Characteristics (xx)

15 CHAPTER 15 Soil Physical Properties 15.1 Bulk Density Particle Density Pore Space Moisture Content by Gravimetric Method Moisture Content at Field Capacity Field Method Using Pressure Plate Apparatus Moisture Content at Permanent Wilting Point Field Method Using Pressure Plate Apparatus Water Holding Capacity Using a Glass Funnel and Cylinder Using Keen and Raczkowski s Box Mechanical Analysis Hydrometer Method Assigning a Textural Class to the Soil based on the Results of Mechanical Analysis CHAPTER 16 Soil Reaction and Acidity 16.1 Soil ph Measurement of Soil ph by ph Meter Half-Cells and Electrodes Reference and Indicator Electrode Common Electrodes in Potentiometry Working of a ph Meter Effect of Electrolytes and Dilution on Soil ph Determination of Soil ph (xxi)

16 16.2 Exchangeable Acidity Extractable Acidity Exchangeable Hydrogen Exchangeable Aluminium CHAPTER 17 Electrical Conductivity and Soluble Salt Content 17.1 Instrumentation in Brief Determination of the Electrical Conductivity of Soils Electrical Conductivity and Total Dissolved Salts CHAPTER 18 Cation Exchange Capacity 18.1 Determination of Cation Exchange Capacity of Soils Methods for the Determination of CEC Ammonium Acetate (NH 4 OAc) Method BaCl 2 Compulsive Exchange Method CHAPTER 19 Preparation of Soil Extracts 19.1 Preparation of Soil Water Extract Preparation of Saturation Extract CHAPTER 20 Soluble Chlorides 20.1 Determination of Soluble Chlorides CHAPTER 21 Soluble Carbonates and Bicarbonates 21.1 Determination of Soluble Carbonates and Bicarbonates (xxii)

17 CHAPTER 22 Total Carbonates 22.1 Determination of Total Carbonates by Different Methods Gravimetric Method Acid Consumption Method CHAPTER 23 Gypsum 23.1 Determination of Gypsum Based upon Calcium Content Electrical Conductivity CHAPTER 24 Gypsum Requirement 24.1 Determination of Gypsum Requirement of Soils CHAPTER 25 Lime Requirement 25.1 Methods of Determining Lime Requirement Lime Requirement of Soils by Buffer Method SMP Buffer Adams-Evans Buffer Mehlich s Buffer Woodruff s Buffer CHAPTER 26 Organic Carbon 26.1 Dry Methods of Organic Carbon Determination Duma s Dry Combustion Method Loss of Soil Mass on Ignition Method Wet Methods of Organic Carbon Determination (xxiii)

18 CHAPTER 27 Nitrogen 27.1 Determination of Total Nitrogen in Soil by Kjeldahl Method Kjeldahl Nitrogen Determination Setup, Modifications, and Automations for Improvement Nitrate Nitrogen by Phenoldisulfonic Acid Method Ammonium Nitrogen Determination by Indophenol Blue Colorimetric Method Determination by Distillation Method Mineralizable Nitrogen by Alkaline Permanganate Method CHAPTER 28 Phosphorus 28.1 Total Phosphorous Organic Phosphorous Citrate Soluble Phosphorous Available Phosphorous By Bray s 1 Method By Olsen s Method CHAPTER 29 Potassium 29.1 Available Potassium Soluble Potassium Exchangeable Potassium Determination of Potassium in the Extracts by Atomic Absorption Spectrophotometry (xxiv)

19 CHAPTER 30 Calcium 30.1 Determination of Exchangeable Calcium Exchangeable and Soluble Calcium by EDTA (Versene) Method Calcium in the Soil Extracts by Atomic Absorption Spectrophotometry CHAPTER 31 Magnesium 31.1 Determination of Exchangeable Magnesium Magnesium in Soil Extracts by EDTA (Versene) Method Magnesium in Soil Extracts by Atomic Absorption Spectrophotometry CHAPTER 32 Sulfur 32.1 Determination of Available Sulfur Available Sulfur by Turbidimetry Sulfate-S by BaSO 4 Gravimetric Precipitation Method CHAPTER 33 Micronutrients 33.1 Iron Determination of Available Iron Content of Soils Determination of Total Iron Content of Soils Zinc Determination of Available Zinc Content of Soils Determination of Total Zinc Content of Soils (xxv)

20 33.3 Manganese Determination of Available Manganese Content of Soils Determination of Total Manganese Content of Soils Copper Determination of Available Copper Content of Soils Determination of Total Copper Content of Soils Nickel Determination of Available Nickel Content of Soils Determination of Total Nickel Content of Soils Boron Available Boron in Soils by Spectrophotometric Method Available Boron by Atomic Absorption Spectrophotometry Molybdenum Determination of Available Molybdenum Content of Soils CHAPTER 34 Beneficial Nutrients 34.1 Sodium Determination of Exchangeable and Soluble Sodium by Flame Photometry Soluble Sodium Exchangeable Sodium Determination of Exchangeable and Soluble Sodium by Atomic Absorption Spectrophotometry Cobalt Determination of Available Cobalt Content of Soils by AAS Determination of Total Cobalt Content of Soils by AAS Determination of Total Cobalt Content of Soils by Spectrophotometry (xxvi)

21 34.3 Silicon Determination of Soluble Silicon Content of Soils CHAPTER 35 Heavy Metals 35.1 Determination of Total Cadmium, Chromium and Lead Content of Soils CHAPTER 36 Part V PLANT ANALYSIS Plant Analysis - Sample Collection and Preparation 36.1 Principal Objectives of Plant Analysis Sampling and Sample Processing for Plant Analysis Collection of Representative Plant Samples Decontamination of the Collected Samples Drying of the Decontaminated Samples Particle Size Reduction of the Decontaminated and Dried Samples Storage of the Decontaminated, Dried and Particle Size Reduced Samples Destruction of Organic Matter Content of the Samples Interpretation of Plant Analysis Results Critical Level and Sufficiency Range Approach DRIS Approach Limitations of Plant Analysis Late Receipt of Results for Remedial Measures Uncounted Factors Alter Nutrient Concentrations Inadequacy in Establishing Two or More Deficient Nutrients with the Same Degree of Certainty Contamination of Samples with Adhered Materials Decomposition of the Samples During Transit Limitation of Determining Only the Total Nutrient Concentration (xxvii)

22 CHAPTER 37 Moisture and Dry Matter Content 37.1 Moisture Content by Gravimetric Method Moisture Content by Using Microwave Oven CHAPTER 38 Nitrogen 38.1 Total Nitrogen Content by Kjeldahl Method Total Nitrogen Content by Automated Combustion Method CHAPTER 39 Phosphorus 39.1 Determination by Colorimetric Methods Molybdenum Blue Method Molybdate-Vanadate Yellow Method Determination by Volumetric Method CHAPTER 40 Potassium 40.1 Determination of Potassium in Plants Flame Photometry Atomic Absorption Spectrophotometry CHAPTER 41 Calcium 41.1 Determination of Calcium in Plants Flame Photometry Atomic Absorption Spectrophotometry Versene Titrimetric Method (xxviii)

23 CHAPTER 42 Magnesium 42.1 Determination of Magnesium in Plants Flame Photometry Atomic Absorption Spectrophotometry Versene Titrimetric Method CHAPTER 43 Sulfur 43.1 Determination of Sulfur by Turbidimetry Sulfate Sulfur in Plant Samples Digested by Wet Oxidation Sulfate Sulfur in Plant Samples Digested by Dry Ashing CHAPTER 44 Micronutrients 44.1 Iron Determination by Atomic Absorption Spectrophotometry Zinc Determination by Atomic Absorption Spectrophotometry Manganese Determination by Atomic Absorption Spectrophotometry Copper Determination by Atomic Absorption Spectrophotometry Nickel Determination by Atomic Absorption Spectrophotometry Boron Determination by Colorimetry / Spectrophotometry Molybdenum Determination by Colorimetry/Spectrophotometry Determination by Atomic Absorption Spectrophotometry (xxix)

24 CHAPTER 45 Beneficial Elements 45.1 Sodium Determination of Sodium in Plants Flame Photometry Atomic Absorption Spectrophotometry Silicon Determination by Colorimetry/Spectrophotometry Part VI WATER ANALYSIS CHAPTER 46 Introduction 46.1 Collection of Water Samples Selection of Containers for Collection of Water Samples Cleaning of Sampling Devices and Sample Containers Method for Collection of Water Sample Types of Water Sampling Preserving the Collected Water Samples Analyses to be Performed CHAPTER 47 Solids in Water 47.1 Total Solids (TS) Determination of Total Solids Total Dissolved Solids (TDS) Determination of Total Dissolved Solids Total Suspended Solids (TSS or TSuS) Determination of Total Suspended Solids (xxx)

25 CHAPTER 48 ph 48.1 Significance of ph of Natural Water Determination of ph CHAPTER 49 Electrical Conductivity 49.1 Conductivity Bridge Determination of Electrical Conductivity of Water Quality of Irrigation Water Based Upon Electrical Conductivity Care and Maintenance of the Conductivity Bridge Temperature Correction of the Conductivity Results CHAPTER 50 Chemical Oxygen Demand (COD) 50.1 Significance of Chemical Oxygen Demand Determination of COD by K 2 Cr 2 O 7 Volumetric Method Determination of COD by K 2 Cr 2 O 7 Spectrophotometric Method CHAPTER 51 Chlorides 51.1 Determination CHAPTER 52 Carbonates and Bicarbonates 52.1 Determination (xxxi)

26 CHAPTER 53 Calcium and Magnesium 53.1 Determination of Soluble Calcium and Magnesium by Versene (EDTA) Method CHAPTER 54 Nitrogen 54.1 Determination of Total Nitrogen Determination by Kjeldahl Method Determination of Ammonium Nitrogen Determination by Kjeldahl Distillation Determination of Nitrate Nitrogen Determination by Kjeldahl Distillation Method Determination of Nitrite Nitrogen Determination by Spectrophotometry CHAPTER 55 Phosphorus 55.1 Significance of Phosphorus in Water Determination of Soluble Phosphorus by Spectrophotometry Determination of Total Phosphorus by Spectrophotometry CHAPTER 56 Potassium 56.1 Determination by Flame Photometry CHAPTER 57 Sodium 57.1 Significance of Sodium in Water Determination by Flame Photometry Quality of Irrigation Water Based on Soluble Sodium Content (xxxii)

27 CHAPTER 58 Sulfur 58.1 Determination of Sulfate Sulfur by Gravimetry Determination of Sulfate Sulfur by Turbidimetry CHAPTER 59 Boron 59.1 Significance of Boron in Water Determination of Boron in Water Spectrophotometry Atomic Absorption Spectrophotometry Judging the Quality of Irrigation Water Based on Boron Content CHAPTER 60 Iron 60.1 Determination of Iron in Water CHAPTER 61 Irrigation Water Quality Appraisal 61.1 Major Criteria for Irrigation Water Quality Appraisal Salinity Hazard Sodium Hazard Alkalinity Hazard Salt Index Permeability Hazard Specific Ion Toxicity Hazard Appendix Laboratory Safety and Work Ethics For Further Reading Index (xxxiii)