Equilibrium: Chemical and Ionic

65 lessons, pages 1766–1830.

  1. Dynamic Chemical Equilibrium — Equal forward and reverse rates in a closed reacting system
  2. Reversible Reactions and Equilibrium State — Approach to constant composition from either direction
  3. The Law of Mass Action — Equilibrium expressions from balanced reaction stoichiometry
  4. Concentration Equilibrium Constant Kc — Writing and interpreting equilibrium concentration ratios
  5. Pressure Equilibrium Constant Kp — Gas partial-pressure expressions for equilibrium
  6. Connecting Kp and Kc — Gas-mole change and the RT conversion in ideal-gas models
  7. Reaction Quotient and Direction of Change — Comparing Q with K before equilibrium is reached
  8. Equilibrium Constants and Reversed Reactions — Reciprocal and exponent rules for rewritten equations
  9. Combining Equilibrium Reactions — Multiplying constants when reaction equations are added
  10. Heterogeneous Equilibrium — Why pure solids and liquids are omitted from simple K expressions
  11. Activities and Standard States — Dimensionless thermodynamic equilibrium constants
  12. Equilibrium and Gibbs Energy — Relating ΔG, Q and K at fixed temperature
  13. Le Chatelier's Principle — Qualitative response to an imposed equilibrium disturbance
  14. Concentration Changes at Equilibrium — Shift in composition after adding or removing a species
  15. Pressure and Volume Changes — Gas-equilibrium response when total volume changes
  16. Temperature Changes and Equilibrium — Changing K for exothermic and endothermic reactions
  17. Catalysts and Equilibrium Position — Faster approach without changing the equilibrium constant
  18. Inert Gas Effects — Contrasting constant-volume and constant-pressure addition
  19. ICE Tables for Equilibrium — Initial, change and equilibrium amount bookkeeping
  20. Solving a Simple Kc Problem — One-variable equilibrium calculation from an ICE table
  21. Small-x Approximations — Testing neglected equilibrium changes after solving
  22. Degree of Dissociation — Fraction reacted and equilibrium composition
  23. Gas Equilibrium from Partial Pressures — Using mole fractions to evaluate Kp
  24. The Haber Equilibrium — Ammonia synthesis yield under temperature and pressure changes
  25. Industrial Equilibrium Compromises — Balancing equilibrium yield, rate and process cost
  26. Electrolytes and Ionic Equilibrium — Strong and weak ionization in aqueous solution
  27. Water Autoionization and Kw — Hydronium and hydroxide relation at a stated temperature
  28. pH and pOH — Logarithmic concentration scales for aqueous ions
  29. Strong Acid and Base Calculations — Stoichiometric ion concentrations with dilution and neutralization
  30. Weak Acid Equilibrium and Ka — Acid dissociation and equilibrium concentration expressions
  31. Weak Base Equilibrium and Kb — Base proton uptake and hydroxide production
  32. Conjugate Acid-Base Pairs — Proton-transfer partners and relative acid-base strength
  33. Ka, Kb and Conjugate Strength — Connecting conjugate constants through Kw
  34. Percent Ionization of Weak Acids — Fraction dissociated as concentration changes
  35. Weak Acid ICE Calculations — Exact and approximate hydrogen-ion concentration solutions
  36. Weak Base ICE Calculations — Solving hydroxide concentration from Kb
  37. Polyprotic Acid Equilibria — Stepwise proton loss and multiple dissociation constants
  38. Amphiprotic Species — Species that can donate or accept a proton
  39. Salt Hydrolysis — Acidic and basic ions generated by dissolved salts
  40. Common-Ion Effect — Shift in weak-electrolyte ionization after adding a shared ion
  41. Buffer Composition and Action — Weak acid-base pairs resisting modest pH change
  42. Henderson-Hasselbalch Relation — Buffer pH from conjugate-base to acid ratio
  43. Buffer Preparation — Selecting acid-base ratios and total concentration
  44. Buffer Capacity and Limits — Amount of added acid or base a buffer can absorb
  45. Acid-Base Titration Curves — pH evolution during controlled neutralization
  46. Strong Acid-Strong Base Titrations — Stoichiometric equivalence and excess-reagent pH
  47. Weak Acid-Strong Base Titrations — Buffer region, half-equivalence and basic equivalence
  48. Weak Base-Strong Acid Titrations — Buffer region and acidic equivalence
  49. Acid-Base Indicators — Indicator transition range and endpoint choice
  50. Solubility Equilibrium and Ksp — Dissolution expression for a sparingly soluble salt
  51. Molar Solubility from Ksp — Converting ion-product stoichiometry into dissolved amount
  52. Ion Product and Precipitation — Comparing Qsp with Ksp to predict direction
  53. Common-Ion Effect on Solubility — Suppressing dissolution through a shared dissolved ion
  54. pH-Dependent Solubility — Acid-base reactions coupled to dissolution
  55. Selective Precipitation — Separating ions using different precipitation thresholds
  56. Complex-Ion Formation and Solubility — Ligand binding coupled to dissolution equilibrium
  57. Coupled Ionic Equilibria — Combining acid-base, dissolution and complexation constraints
  58. Charge Balance in Aqueous Equilibrium — Electroneutrality as a constraint on ion concentrations
  59. Mass Balance in Ionic Equilibrium — Accounting for all dissolved forms of one chemical component
  60. Approximations in Ionic Equilibrium — Testing simplifying assumptions against calculated concentrations
  61. Chemical Equilibrium Mixed Problems — Combining K, Q, disturbances and reaction extent
  62. Ionic Equilibrium Mixed Problems — Integrating pH, buffers, titrations and solubility
  63. Equilibrium Graphs and Data — Reading concentration-time and pH-volume plots
  64. Equilibrium Misconceptions and Checks — Auditing K expressions, shifts, logarithms and assumptions
  65. Equilibrium: Chemical and Ionic Review — Connecting reaction equilibrium with aqueous ion behavior