Chapter 8 Equilibria Containing Metal Ions Equilibria with (Transition) Metal Ions Can involve one or more of the following Acid-base equilibria Complex ion equilibria Solubility equilibria Metal Complex Ions - Jargon Complex ion: ionic species consisting of a metal ion bonded to one or more Lewis bases Coordinate bond: bond formed when one anion/molecule donates a pair of electrons to another ion/molecule to form a covalent bond Ligand: a Lewis base bonded to the central metal ion of a complex ion. Inner coordination sphere: ligands that are bond directly to a metal via coordinate covalent bonds. Common Ligands (Lewis Bases) Lewis Acids and Bases Lewis Base: Substance that donates a lone pair of electrons. Lewis Acid: Substance that accepts a lone pair of electrons Hydrated Metal Ions as Acids Ka Values of Hydrated Metal Ions Solubility Equilibria & Solubility Product (Ksp) Dissolution of Mg(OH)₂(s):- Solubility: Amount of solute that dissolves, g/L- Molar Solubility: Amount of dissolved solute expressed as mole/L- Solubility Product COnstant: Ksp Molar Solubility Molar solubility is calculated by solving the equilibrium problem (I.C.E. Table) Initial: (solid) ------ ------ Change: +x +2x Equilibrium: (x) (2x) Another Molar Solubility Example Factors Affecting Solubility Common ion effect: Add common ion from another source: Sample Exercise -- Common Ion Effect Additional Factors Affecting Solubility pH: For insoluble salts containing basic anions, solubility increases as pH decreases. Add acid (H+), reacts with basic anion: Ksp vs Qip (ion product): Will a Precipitate Form? Sample Exercise -- Qip and Ksp Sample Exercise -- Separation of Ions Complex-Ion Equilibria (Formation Constant, Kf) Sample Exercise using Kf Competing/Simultaneous