Advanced Ionic Equilibrium

60 lessons, pages 2481–2540.

  1. Advanced Ionic Equilibrium: The Species View — Simultaneous acid-base, charge-balance and solubility equilibria
  2. Activities Versus Concentrations — Why equilibrium constants are defined with activities
  3. Ionic Strength and Effective Activity — Background electrolyte effects and qualitative activity coefficients
  4. Mass Balance in Aqueous Systems — Conservation equations across dissolved chemical species
  5. Charge Balance in Aqueous Systems — Electroneutrality and including spectator ions
  6. Choosing Equations for Ionic Equilibrium — Independent equilibria, balances and unknown species
  7. Approximations and Their Verification — Small-x tests and error checks in acid-base calculations
  8. Water Autoionisation in Dilute Solutions — When water's H⁺ and OH⁻ contributions cannot be ignored
  9. Temperature Dependence of Kw and pH — Neutrality, temperature and avoiding a fixed-pH slogan
  10. Monoprotic Acid Speciation — Fraction protonated and deprotonated as pH varies
  11. Polyprotic Acids and Stepwise Ka Values — Sequential proton loss and distinct equilibrium constants
  12. Diprotic Acid Species and Charge — H₂A, HA⁻ and A²⁻ mass and charge accounting
  13. First-Dissociation Approximation for Diprotic Acids — Conditions under which Ka1 controls initial pH
  14. Second Dissociation and Its Contribution — Estimating A²⁻ and testing neglected proton release
  15. Diprotic Distribution Fractions — Alpha fractions as functions of H⁺, Ka1 and Ka2
  16. Triprotic Acid Speciation — Four protonation states and three stepwise equilibria
  17. Phosphoric Acid as a Triprotic Example — H₃PO₄ family and pH-dependent dominant species
  18. Carbonate System Equilibria — Carbonic-acid family, dissolved CO₂ and bicarbonate
  19. Amphiprotic Intermediate Ions — Species that can both donate and accept a proton
  20. pH of Amphiprotic Salt Solutions — Approximate midpoint relation and its assumptions
  21. Polyprotic Acid Titration Stages — Successive equivalence points and species changes
  22. Overlapping Polyprotic Equilibria — When similar stepwise Ka values obscure separate stages
  23. Buffer Action Revisited — Conjugate-pair consumption of added H⁺ and OH⁻
  24. Henderson–Hasselbalch from Ka — Derivation, activities and ratio interpretation
  25. Selecting a Buffer Pair — Target pH, pKa and chemically compatible components
  26. Buffer Ratio Design — Choosing acid-to-base proportions for target pH
  27. Buffer Capacity — Resistance to added acid or base and total concentration
  28. Buffer Capacity Near pKa — Why equal conjugate-pair amounts balance acid and base response
  29. Preparing Buffers by Partial Neutralisation — Stoichiometry before equilibrium for weak acid and strong base
  30. Preparing Buffers from Weak Base and Strong Acid — Controlled protonation and remaining base accounting
  31. Response of a Buffer to Strong Acid — Mole ledger before revised pH calculation
  32. Response of a Buffer to Strong Base — Neutralisation of weak-acid component and capacity limits
  33. Dilution of Buffers — Nearly constant ratio pH versus declining capacity
  34. Mixing Two Buffer Solutions — Conjugate-pair mole balances and equilibrium re-establishment
  35. Polyprotic Buffer Regions — Selecting a relevant conjugate pair near a stepwise pKa
  36. Phosphate Buffer Design — H₂PO₄⁻/HPO₄²⁻ ratio and realistic assumptions
  37. Carbonate Buffer Design — Bicarbonate-carbonate balance and gas exchange cautions
  38. Buffers and Biological pH — Open-system bicarbonate and phosphate roles
  39. Buffer Failure and Extremes — Exhaustion, very unequal ratios and strong-acid excess
  40. Buffer Design Integrated Problems — Target pH, volume, composition and capacity together
  41. Hydrolysis of Salts in Advanced Problems — Conjugate acid-base behavior and competing equilibria
  42. Weak-Acid Strong-Base Titration Curves — Initial, half-equivalence and equivalence-region calculations
  43. Weak-Base Strong-Acid Titration Curves — Protonation stages and acidic equivalence region
  44. Indicator Choice and Titration Error — Transition range versus steep pH region
  45. Solubility Product as an Equilibrium Constant — Ksp expressions from dissolution stoichiometry
  46. Molar Solubility from Ksp — Stoichiometric exponents for AB and AB₂ salts
  47. Ion Product and Precipitation Direction — Comparing Qsp with Ksp before and after mixing
  48. Common-Ion Suppression of Solubility — Mass-action shift and controlled approximation
  49. Dissolution by Acid-Base Consumption — Protonation of basic anions and conditional solubility
  50. Complexation and Apparent Solubility — Free-metal reduction by ligand binding
  51. Conditional Solubility Products — Activities, pH and complexation behind measured solubility
  52. Onset of Precipitation — Threshold ion concentration from Ksp and a counter-ion level
  53. Selective Precipitation of Two Cations — Comparing onset thresholds and separation windows
  54. Fraction Remaining During Selective Precipitation — Residual dissolved ion when the second solid begins
  55. Selective Sulfide Precipitation — pH-dependent sulfide availability and metal-sulfide Ksp
  56. Selective Hydroxide Precipitation — Metal-hydroxide thresholds controlled by pH
  57. Amphoteric Hydroxides and Re-Dissolution — Precipitation then complex formation in excess base
  58. Precipitation After Mixing Solutions — Dilution, ion product and material-balance checks
  59. Advanced Ionic Equilibrium Integrated Problems — Coupled acid-base, buffer and solubility reasoning
  60. Advanced Ionic Equilibrium Review — Evidence-led choice of balances, constants and approximations