Survival guide to general chemistry

Description

Preface............................................................................................................................................xvii Authors ............................................................................................................................................xix Chapter 1 Unit Conversion and Density: An Introduction to Problem-Solving Methods ............1 I General Techniques for Performing Unit Conversions .....................................1 II General Procedures for Solving Density Problems ...........................................3 Process for Density Problems ............................................................................3 III General Examples for Density with Unit Conversions ......................................3 IV Practice Problems ..............................................................................................6 V Answers to Practice Problems ...........................................................................7 Chapter 2 Atomic Particles, Isotopes, and Ions: An Initial Look at Atomic Structure .............. 11 I General Concepts ............................................................................................ 11 II Atomic Symbols and Isotopes ......................................................................... 13 Isotopes: Atoms with the Same Value of Z But with a Different Value for A .....14 III Atomic Symbols and Ion Symbols .................................................................. 15 Additional Practice Examples ......................................................................... 16 IV Practice Problems ............................................................................................ 17 V Answers to Practice Problems ......................................................................... 17 Chapter 3 Working with Atomic Mass and Nuclear Mass ......................................................... 19 I General Concepts ............................................................................................ 19 II Potential Energy, Kinetic Energy, and Forces ................................................. 19 III Energy, Mass Loss, and the Strong Nuclear Force ..........................................20 IV Calculating Mass Using the Atomic Mass Unit ..............................................22 V Calculating the Approximate Mass of an Atom in amu, kg, or g ...................23 Process for Calculating Atomic Masses ..........................................................23 VI Average Atomic Mass for an Element .............................................................25 VII Practice Problems ............................................................................................26 VIII Answers to Practice Problems .........................................................................27 Chapter 4 Procedures for Writing Formulas and Naming Compounds ..................................... 31 I General Concepts ............................................................................................ 31 II Elemental Ions for Ionic Compounds .............................................................. 32 III Writing Formulas for Binary Ionic Compounds ............................................. 33 IV Naming Binary Ionic Compounds ..................................................................36 Procedure for Naming a Binary Ionic Compound ...........................................36 Additional Concepts ........................................................................................37 Additional Practice Examples .........................................................................38 V Writing Formulas for Ionic Compounds with Polyatomic Ions ......................39 Procedure for Writing Formulas for Ionic Compounds with Polyatomic Ions ........................................................................................39 VI Naming Ionic Compounds with Polyatomic Ions ............................................40 Procedure for Naming Ionic Compounds Containing Polyatomic Ions .......... 41 VII Naming Binary Covalent Compounds ............................................................ 41 Covalent System for Naming Binary Covalent Compounds ........................... 42 VIII Additional Combination Practice Examples ................................................... 43 IX Practice Problems ............................................................................................46 X Answers to Practice Problems .........................................................................46 Chapter 5 An Introduction to Moles and Molar Mass ................................................................49 I General Concepts ............................................................................................49 Counting Numbers ...........................................................................................49 II Mass/Mole/Atom Conversions for Elements ................................................... 51 Procedure for Solving Mole Problems (Elements) .......................................... 51 III Mass/Mole/Molecule Conversions for Compounds ........................................ 53 Procedure for Solving Mole Problems (Compounds) .....................................54 IV Concepts for Using Ratios in Formulas ........................................................... 55 V Mass Percent of an Element in a Compound ...................................................58 VI Practice Problems ............................................................................................60 VII Answers to Practice Problems ......................................................................... 61 Chapter 6 Procedures for Calculating Empirical and Molecular Formulas ...............................69 I General Concept ..............................................................................................69 Concepts of Empirical or Molecular Formulas ...............................................69 II Procedure for Calculation of Simplest (Empirical) Formula of Any Compound ...........................................................................................69 III Determination of the Simplest Formula from Element Mass Percent ............. 71 IV Determination of the True Molecular Formula for Molecules ........................72 Determining and Using the Multiple ...............................................................72 Procedure for Finding the Simplest Formula and True Molecular Formula........73 V Experimental Determination of Compound Formulas ....................................73 VI Practice Problems ............................................................................................ 76 VII Answers to Practice Problems .........................................................................77 Chapter 7 Writing Chemical Equations ......................................................................................83 I General Concepts ............................................................................................83 Conservation Laws ..........................................................................................83 II Writing Balanced Equations ............................................................................83 Process for Writing Balanced Equations from Descriptions ...........................84 III Practice Problems ............................................................................................86 IV Answers to Practice Problems .........................................................................86 Chapter 8 Techniques for Performing Stoichiometric Calculations ...........................................89 I General Concepts ............................................................................................89 II General Process for Stoichiometric Calculations Based on Balanced Equations ....................................................................................................90 Diagram Form.................................................................................................. 91 Viewing Each Step ...........................................................................................92 III Percent Yield .....................................................................................................93 IV Limiting Reagent ..............................................................................................94 V Calculation of All Products and Reactants in a Limiting Reagent Problem ....96 VI Practice Problems ...........................................................................................100 VII Answers to Practice Problems ........................................................................ 102 Chapter 9 Precipitation and Acid/Base Aqueous Reactions: Concepts and Methods to Design Complete Balanced Equations ..................................................................... 109 I General Concepts ............................................................................................ 109 II Solubility Equations and Aqueous Solution Formats ..................................... 109 Solution Formation Equations ........................................................................ 110 Formula Format .............................................................................................. 110 Ionic Format .................................................................................................... 111 Equation Formats for Complete Aqueous Solution Reactions ....................... 111 Formula Format Equation ............................................................................... 111 Total Ionic Format Equation ........................................................................... 111 Net Ionic Equation .......................................................................................... 112 III Precipitation Reactions ................................................................................... 113 Determining Ionic Compound Solubility ....................................................... 113 General Solubility Guideline Rules ................................................................ 114 Examples from the Previous Reactions .......................................................... 114 Predicting Products for Precipitation Reactions and Writing Equations ........ 114 Process for Completing and Writing Precipitation Reaction Equations ......... 114 IV Acid/Base Reactions: General Concepts ........................................................ 118 Properties of Acids .......................................................................................... 119 Properties of Bases..........................................................................................120 V Aqueous Acid/Base Reactions ........................................................................ 121 Acid Ionization Reaction and Acid Strength .................................................. 121 Aqueous Base Reactions ................................................................................. 122 Completing Acid/Base Reactions and Equations ........................................... 122 Examination of Reaction Requirements ......................................................... 123 A Specific Process for Completing and Writing Acid/Base Reaction Equations ....................................................................................124 VI Practice Problems ........................................................................................... 127 VII Answers to Practice Problems ........................................................................ 128 Chapter 10 Oxidation Numbers: A First Look at Redox Reactions ........................................... 131 I General Concepts ............................................................................................ 131 II Oxidation Numbers ......................................................................................... 133 General Rules for Oxidation Numbers ........................................................... 133 III Process for the Analysis of Redox Reactions Using Oxidation Numbers ....... 135 IV Practice Problems ........................................................................................... 138 V Answers to Practice Problems ........................................................................ 138 Chapter 11 Solution Concentration, Molarity, and Solution Stoichiometry ............................... 141 I General Concepts ............................................................................................ 141 II Concentration Calculations Based on Molarity .............................................. 142 General Procedure for Solving Molarity Problems ........................................ 142 III Solution Stoichiometry .................................................................................. 145 Process for Solution Stoichiometry ............................................................... 145 IV Practice Problems .......................................................................................... 148 V Answers to Practice Problems ....................................................................... 149 Chapter 12 Light, Matter, and Spectroscopy .............................................................................. 153 I General Properties of Light ........................................................................... 153 Wave Properties ............................................................................................. 153 The Wave Nature of Light ............................................................................. 153 II Energy and the Quantum Theory of Light .................................................... 154 Energy and Light Calculations ...................................................................... 155 III Electrons and Atoms ..................................................................................... 156 IV Energy States, Light Interaction, and Electron Transitions ........................... 157 V Spectroscopy Calculations ............................................................................ 157 VI Spectra Calculations Using [E (Final Level) − E (Initial Level)] .................. 159 VII Practice Problems .......................................................................................... 161 VIII Answers to Practice Problems ....................................................................... 162 Chapter 13 Atomic Orbitals and the Electronic Structure of the Atom ..................................... 167 I Quantum Theory and Electron Orbitals ........................................................ 167 Orbital Architecture and Electron Spin ......................................................... 169 II Determining Electron Configurations of Elements ....................................... 170 Rules for Ground State Electron Configurations ........................................... 171 Closed Shells and the Noble Gas Electron Configuration ............................. 173 III Electron Configurations and Organization of the Periodic Table ................. 175 Process to Read the Electron Configuration Directly from the Periodic Table ........................................................................................... 176 Valence Shell Electrons ................................................................................. 177 IV Ionization Energy and Electron Configuration Relationship ........................ 178 V Determination of Electron Configuration for Ions ........................................ 180 Electron Configuration for Negative Ions ...................................................... 180 Electron Configuration for Most Fixed-Charge Positive Ions ....................... 181 Ion Formation for Metals in Groups 4A and 5A ........................................... 182 Ion Formation for Transition Metals (B Groups) .......................................... 182 VI Practice Problems .......................................................................................... 183 VII Answers to Practice Problems ....................................................................... 183 Chapter 14 Alternate Methods for Visualizing and Constructing: Lewis Structures of Covalent Molecules .................................................................................................. 185 I Introduction to Interpretation of Lewis Structures ........................................ 185 II Common Bonding Behavior for Non-Metals in Covalent Molecules ........... 186 General Concept of Normal Bonding in Covalent Molecules ....................... 186 Normal Neutral Bonding Rules ..................................................................... 187 Summary of Normal Neutral Bond Numbers for H, Be, B, C, N, O, F ........ 188 Summary of Normal Neutral Bond Numbers for Elements in Rows 3–5 ..... 190 III Constructing Lewis Structures for Covalent Molecules from H and the Row-2 Elements: Bonding That Follows Normal Neutral Bonding Rules ..... 190 Lewis Structure Concepts ............................................................................... 190 Process for Molecules Containing H, Be, B, C, N, O, F ................................ 191 IV Constructing Lewis Structures for Covalent Molecules Using Elements from Rows 3–5: Bonding Patterns That Follow Normal Neutral Bonding Rules ............................................................................................ 195 V Constructing Molecules That Require Exceptions to Normal Neutral Bonding Rules ............................................................................................ 198 Bonding Patterns through Exception Rules .................................................... 199 Exception Rule #1 .............................................................................200 Exception Rule #2 .............................................................................200 Exception Rule #3 .............................................................................200 Working with Exception Rule #1 ....................................................................200 Lewis Structures for Polyatomic Ions ............................................................. 201 Using Exception Rule #3 ................................................................................203 Other Uses for Exception Rules .....................................................................204 Resonance Structures ......................................................................................204 VI Practice Problems ...........................................................................................205 VII Answers to Practice Problems ........................................................................206 Chapter 15 Additional Techniques for Designing and Representing Structures of Large Molecules .......................................................................................................209 I Techniques for Understanding and Designing Isomers of Large Molecules .................................................................................209 General Rule #1 for the Number of Multiple Bonds (or Rings) .....................209 II Using Condensed Structural Formulas ........................................................... 213 Guidelines for Converting a Full Structure to a Condensed Structural Formula ..................................................................................... 213 Guidelines for Expanding Condensed Formulas: Reconstructing the Complete Molecule .................................................................................... 216 III Concept of Ring Structures and Line Drawings ............................................. 217 Structural Notation: Guidelines for Producing Line Drawings ...................... 218 Converting Line Drawings to Structural Formulas ......................................... 219 IV Practice Problems ........................................................................................... 219 V Answers to Practice Problems ........................................................................220 Chapter 16 Determining and Drawing Molecular Geometry and Polarity ................................223 I Concepts of Molecular Geometry...................................................................223 Types of Geometry Analysis for Central Atoms .............................................223 Counting Electron Regions .............................................................................223 Summary of E.R. Count ..................................................................................224 II Process for Complete Determination of Molecular Geometry and Polarity ..... 224 Descriptions of Geometric Figures for 2 to 4 Electron Regions .....................225 Descriptions of Geometric Figures for 5 and 6 Electron Regions ..................225 III Atom Geometry Determination from Electron Region Geometry ...............228 Additional Atom Geometries Derived from Trigonal Planar and Tetrahedral .......................................................................................229 Additional Atom Geometries Derived from Trigonal Bipyramidal and Octahedral ..........................................................................................230 IV Molecular Polarity ......................................................................................... 233 V Practice Problems ..........................................................................................238 VI Answers to Practice Problems .......................................................................238 Chapter 17 Summary Analysis of Central Atom Bonding, Hybridization, and Geometry ........243 I Concept of Sigma Bonds and Pi Bonds .........................................................243 II Concept of Hybridization ..............................................................................244 Electron Configuration and Hybridization of Carbon in CH4 .......................245 III Summary Tables ............................................................................................248 IV Practice Problems ..........................................................................................250 V Answers to Practice Problems ....................................................................... 251 Chapter 18 Concepts of Potential Energy, Enthalpy, and Bond Energy Calculations ................ 253 I Concept of Energy ......................................................................................... 253 II Chemical Bond Energetics ............................................................................254 Bond Strengths and Bond Dissociation Energy (BDE) ................................. 255 III Energy and Chemical Reactions ...................................................................256 Potential Energy Changes and Enthalpy .......................................................256 IV Potential Energy Diagrams ........................................................................... 257 Activation Energy ..........................................................................................258 V Calculating Reaction Enthalpy Values ..........................................................260 Process for Calculation of ΔH (Reaction) for a Balanced Equation ..............260 VI Reading an Energy Diagram .........................................................................264 VII Practice Problems ..........................................................................................265 VIII Answers to Practice Problems .......................................................................266 Chapter 19 Thermochemistry Calculations: Heat Capacity and Enthalpy .................................269 I General Concepts of Thermodynamics .........................................................269 The First Law of Thermodynamics ............................................................... 270 II Heat Capacity and Heat Transfer between Substances ................................. 271 Simple Heat Transfer for One Substance ...................................................... 273 Simple Heat Transfer between Two Substances ............................................ 274 III Energy and Enthalpy in Chemical Reactions ................................................ 278 IV Calorimetry ................................................................................................... 279 Determining ∆H and ∆E from Calorimetry ..................................................280 General Procedures for Solving Calorimetry Problems ................................280 V Enthalpy and Hess’s Law ...............................................................................284 Process for Applying Hess’s Law Calculations .............................................285 VI Calculation of ∆H (Reaction) from Enthalpies of Formation .......................287 VII Enthalpy and Stoichiometric Calculations .................................................... 291 VIII Practice Problems ..........................................................................................294 IX Answers to Practice Problems .......................................................................297 Chapter 20 Working with Gas Laws ...........................................................................................307 I Kinetic Theory of Gases ................................................................................307 Kinetic Energy, Temperature, and Graham’s Law for Diffusion ..................307 II The Ideal Gas Law ........................................................................................ 310 Measurements of Gas Pressure ...................................................................... 310 Solving Ideal Gas Law Problems .................................................................. 311 III Condition Changes for a Specific Gas Sample .............................................. 313 IV Solving Additional Problems Using Gas Laws ............................................. 315 Stoichiometric Calculations Using Gas Laws ............................................... 316 V Gas Mixtures and Law of Partial Pressures .................................................. 316 VI Practice Problems .......................................................................................... 319 VII Answers to Practice Problems .......................................................................320 Chapter 21 Guideline for Analyzing Intermolecular Forces and Calculating Phase Change Enthalpies ......................................................................................... 325 I Overview of Interparticle and Intermolecular Forces ................................... 325 Phase Changes and Temperature ................................................................... 325 Descriptions of Interparticle Forces .............................................................. 326 II A Guideline for Comparing Total Strength of Intermolecular Forces in Individual Compounds ......................................................................... 328 Strengths of Interparticle Forces ................................................................... 328 Process for Comparing Total Intermolecular Forces for Different Compounds ............................................................................................... 328 III Enthalpy of Phase Changes ........................................................................... 333 IV Interparticle and Intermolecular Forces for Solutions................................... 336 Solubility Requirements ................................................................................ 336 Interparticle and Intermolecular Forces between Solutes and Solvents ........ 337 Process for Comparing Total Intermolecular Forces for Solutions ............... 337 V Enthalpies of Solutions .................................................................................. 339 VI Practice Problems ..........................................................................................340 VII Answers to Practice Problems ....................................................................... 341 Chapter 22 Kinetics Part 1: Rate Laws, Rate Equations, and an Introduction to Reaction Mechanisms ..............................................................................................................345 I General Concept of Kinetics .........................................................................345 Additional Variables Affecting Reaction Rates ............................................345 Information Relationships for Kinetics and Mechanisms .............................346 II Introduction to Reaction Mechanisms ...........................................................346 III Description of Reactions by Mechanisms ..................................................... 347 Variability of Mechanisms ............................................................................ 347 IV Experimental Kinetics: Determining Reactant Orders and Rate Constants from Integrated Rate Equations ...............................................348 Zero-Order Reactants ....................................................................................349 First-Order Reactants ....................................................................................349 Second-Order Reactants ................................................................................ 352 Experimental Determination of Reactant Orders in Multiple- Concentration Rate Expressions ............................................................... 354 V Determining Rate Expressions from Initial Rate Data Calculations ............ 356 Relative Rate Measurements in the Balanced Equation ................................ 356 Working with Initial Rate Data Tables .......................................................... 357 Techniques for Solving for Reactant Orders by Comparing Data Sets ......... 357 Reactant Order Determination by Simple Inspection ................................... 358 Reactant Order Determination by Logarithmic Analysis .............................. 359 Determining the Complete Rate Expressions ............................................... 361 Determining the Value for the Rate Constant ............................................... 361 Determining the Value for Any Unknown Rate ............................................ 361 Determining Reactant Orders from Limited Data Sets ................................ 363 VI Practice Problems ..........................................................................................364 VII Answers to Practice Problems .......................................................................365 Chapter 23 General Techniques for Solving Equilibrium Problems .......................................... 371 I Concentration Quotient and Equilibrium Expression ................................... 371 Equilibrium Types and Expressions .............................................................. 372 II Techniques for Performing Equilibrium Calculations: Calculating K .......... 374 Process for Calculating the Numerical Value of the Equilibrium Constant (K) from Concentrations ........................................................... 375 III Techniques for Performing Equilibrium Calculations ..................................380 Process for Calculating Equilibrium Concentrations of All Reactants and Products from the Numerical Value of the Equilibrium Constant (K) .........................................................................380 IV Techniques for Performing Equilibrium Calculations ..................................384 Using the Quadratic Formula ........................................................................384 V Techniques for Performing Equilibrium Calculations ..................................388 Using the Simplification Technique ..............................................................388 The Common Ion Effect ................................................................................390 VI Shifts in Equilibrium ..................................................................................... 391 VII Practice Problems .......................................................................................... 393 VIII Answers to Practice Problems ....................................................................... 395 Chapter 24 Kinetics Part 2: Application of Rate Laws and Rate Variables to Reaction Mechanisms ..............................................................................................................407 I Predicting Rate Expressions from Mechanisms ............................................407 II General Concepts for Rate Expression Comparison: Identification of the Rate Determining Step .......................................................................407 III Rules and Procedures for Predicting Rate Expressions ................................408 Rule 4 Procedure for Predicting Rate Expressions for Multi-Step Reactions ...................................................................................................409 IV Determining Rate Expressions from Mechanism Descriptions ....................409 Notation for Mechanisms Written in Equation Form ....................................409 Comparison of Rate Expressions for Mechanisms #1, #2, #3 ....................... 411 V General Construction of Potential Energy Diagrams .................................... 414 VI Energy, Temperature, and Chemical Reactions ............................................ 416 Bonding Changes and Activation Energy ..................................................... 416 Bonding Changes and Temperature .............................................................. 416 Relationship between Rate Constant, Temperature, and Ea.......................... 417 VII Reading Potential Energy Diagrams ............................................................. 418 VIII Rates and Catalysis ........................................................................................ 422 IX Practice Problems .......................................................................................... 423 X Answers to Practice Problems .......................................................................426 Chapter 25 Thermodynamics: Entropy and Free Energy ........................................................... 433 I General Concepts of Entropy ........................................................................ 433 Predicting Entropy Changes for a Chemical Process .................................... 433 II Entropy and the Second Law of Thermodynamics ....................................... 436 III Calculation of Entropy and the Third Law of Thermodynamics .................. 438 IV Enthalpy, Entropy, and Chemical Spontaneity .............................................. 441 Enthalpy and Chemical Spontaneity .............................................................442 Entropy and Chemical Spontaneity ...............................................................442 Combining Enthalpy and Entropy as Spontaneity Measures ........................442 Spontaneity and Temperature ........................................................................443 V Reaction Spontaneity and Free Energy .........................................................445 Definition of Free Energy (ΔG) .....................................................................445 Enthalpy, Entropy, and Temperature Contributions to Free Energy .............446 Standard Free Energy (ΔG°) ..........................................................................447 Calculation of ΔG° at Variable Temperatures ............................................... 450 VI Non-Standard Free Energy (ΔG) and Concentrations ................................... 454 Calculating Non-Standard Free Energy (ΔGT) .............................................. 455 VII Non-Standard Free Energy (ΔG) and Equilibrium Constants ....................... 457 VIII Comprehensive Examples .............................................................................460 IX Practice Problems ..........................................................................................463 X Answers to Practice Problems .......................................................................465 Chapter 26 Acid/Base Equilibrium, pH, and Buffers ................................................................. 473 I Acid and Base Dissociation Reactions: Acid and Base Strength .................. 473 Autoionization of Water................................................................................. 476 II Relationship between Acid (pka) and Conjugate Base Strength .................... 476 III Process for Determining the Equilibrium Position for Acid/Base Reactions ................................................................................................ 478 IV pH Calculations in Aqueous Solutions: General Concept of pH ................... 481 V pH Calculations in Aqueous Solutions: Reactions of One Acid or Base with Water ........................................................................................482 VI pH Calculations in Aqueous Solutions: Solving General Acid/Base Reactions .......................................................................................................488 VII The Common Ion Effect and Acid/Base Buffers ..........................................494 VIII The Hendersen–Hasselbach Equation ...........................................................496 IX Practice Problems ..........................................................................................497 X Answers to Practice Problems ....................................................................... 498 Index ......................................................................................................507