4.1 – General Solution Properties Solution – Homogeneous mixture -Aqueous Solution – Solvent is water Solvent – One of larger amount Solute – One of smaller amount Electrolyte – Substance that conducts electricity when dissolved in water. Dissociates into ions (ex-ionic, acids, bases) Nonelectrolyte – Substance that does not conduct electricity when dissolved in water (most molecular compounds)
Electrolytes Open File “SALT WATER CONDUCTIVITY” in AP Power Point folder using Real Player http://www.youtube.com/watch?v=NdG3wK9kNcg
Ionic Compounds in Water Dissociates = Each ion separates from the solid structure and disperses through the solution. Solvation = Ions become surrounded by water molecules. Prevents the ions from recombining. When water is the solvent, AKA hydration.
Ionic Compounds in Water Dissociates = Each ion separates from the solid structure and disperses through the solution. Solvation = Ions become surrounded by water molecules. Prevents the ions from recombining.
Molecular Compounds in Water Ionization = Become ions, especially when dissolving in water. Used typically referring to molecular electrolytes. HCl(g) H + (aq) + Cl - (aq) H2OH2O
4.2 – Precipitation Reactions Precipitation Rxn – Results in a precipitate Precipitate – Insoluble solid (typically formed from two solutions)
4.2 – Precipitation Reactions Solubility – The maximum amount of solute that will dissolve in a given quantity of solvent at a specific temp Insoluble – A substance that does not dissolve. Specifically, the solubility must be less than 0.01 mol/L to be considered insoluble.
Solubility Rules 1. Group 1 & Ammonium cmpds are soluble 2. Nitrates, Bicarbonates, Chlorates are soluble 3. Halides are soluble except Ag, Hg 2 2+, Pb 4. Sulfates are soluble except Ag, Ca, Sr, Ba, Pb 5. Carbonates, phosphates, chromates, sulfides are insoluble
Types of Redox Reactions 1.Combination -Two or more reactants from a single product -Combustion of Magnesium metal
Types of Redox Reactions 2.Decomposition -Break down into 2 or more products -Decomposition of mercury (II) oxide -Elephant’s Toothpaste Dawn detergent 30% hydrogen peroxide (H 2 0 2 ) saturated solution of potassium iodide (KI)
Types of Redox Reactions 3.Single Displacement Reactions -An atom or ion in a compound is displaced by another a. -Hydrogen displacement: -Group 1, Ca, Sr, Ba can displace from water -Al & Fe can replace from steam -Many metals can replace from Acids (ex – Zn)
b. Metal Displacement -Use activity series -Elements high on the list can remove lower elements from a compound