Ions in Aqueous Solutions Dissociation Ionization Strong and Weak Electrolytes Colligative Properties Vapor-Pressure Lowering Freezing Point Depression Boiling Point Elevation Osmotic Pressure Electrolytes and Colligative Properties

Ions in Aqueous Solutions Dissociation: the separation of ions that occurs when an ionic compound dissolves Ionization Strong and Weak Electrolytes

Ions in Aqueous Solutions Dissociation: the separation of ions that occurs when an ionic compound dissolves AX → A+ + X- Precipitation Reactions: Net Ionic Equations

Ions in Aqueous Solutions Precipitation Reactions: Soluble Most Sodium, Potassium, and Ammonium compounds are soluble Most Nitrates, Acetates, and Chlorates are soluble Most Chlorides are soluble Except Silver, Mercury(I), and Lead Lead(II)Chloride is Soluble in Hot H2O Most Sulfates are soluble Except those with Barium, Strontium, and Lead

Ions in Aqueous Solutions Precipitation Reactions: Insoluble Insoluble: most Carbonates, Phosphates, and Silicates Except with Sodium, Potassium, Ammonium Insoluble most Sulfides Except with Calcium, Strontium, Sodium, Potassium, and Ammonium Net Ionic Equations Net Ionic Equations: Include only the compounds and ions that change in the reaction Spectator Ion: Ions that remain unchanged from the beginning to end of the reaction

Ions in Aqueous Solutions Ionization Ionization: when ions are formed from solute molecules by the action of the solvent Hydronium Ion: H3O+ or H+

Ions in Aqueous Solutions Strong and Weak Electrolytes Strong Electrolytes: A compound that conducts electricity well in an aqueous solution Good Conductivity is usually due to high dissociation of the compound into ions Weak Electrolytes: A compound that conducts electricity poorly in an aqueous solution Poor Conductivity is usually due to low dissociation of the compound into ions

Colligative Properties Colligative Properties: properties that depend on solute particle concentration not their identity Vapor-Pressure Lowering Freezing Point Depression Boiling Point Elevation Osmotic Pressure Electrolytes and Colligative Properties Actual Values for Electrolyte Solutions: approximations

Colligative Properties Vapor-Pressure Lowering Nonvolatile: a substance with little tendency to become a gas under existing conditions

Colligative Properties Freezing Point Depression Molal Freezing Point Constant (Kf): the freezing point depression of the solvent in a 1 molal solution of a nonvolatile non-electrolytic solute. Freezing Point Depression (Δtf ) the difference between the freezing point of a pure solvent and a solvent of a non-electrolytic solvent Freezing Point Depression = molal freezing point depression x molality, Δtf = (Kf)m

Colligative Properties Boiling Point Elevation Molal Boiling Point Constant (Kb): the boiling point elevation of the solvent in a 1 molal solution of a nonvolatile no electrolytic solute. Boiling Point Elevation (Δtb ) the difference between the freezing point of a pure solvent and a solvent of a non-electrolytic solvent Boiling Point Elevation = molal boiling point elevation x molality, Δtb = (Kb)m

Colligative Properties Osmotic Pressure Semipermeable Membranes: allows the movement of some particles while block others Osmosis: the movement of the solvent through a semipermeable membrane from the side of lower solute concentration to the side with greater solute concentration Osmotic Pressure: the external pressure necessary to stop the process of Osmosis.

Colligative Properties Electrolytes and Colligative Properties Calculated Values for Electrolytic Solutions: is proportional to the moles of ions produced Actual Values for Electrolyte Solutions: approximations