Notes Sept 10 2013 Talked about chemical equations balancing equations equilibrium reactions reversible Aqueous solutions 1 Dissolve reactants 2 What happens when a solute dissolves solvent is what it dissolves into in this case water When ionic compounds dissolve they become the ions they are made up of Dissolving Dissolution Macroscopic see vs Microscopic How do we know Conductivity to test if there are ions in the solution to find out if the ionic compound dissolved o Will light the bulb if there are ions in the solution o Molecular compound dissolved in solution it won t have ions so light bulb isn t lit ConcepTest Which materials give the indicated result when subjected to the conductivity test Sodium acetate aq dimly lit ionic compound brightly lit Table sugar or sucrose aq unlit true Sulfuric acid aq brightly lit strong acid H HSO4 true i ii iii A I ii iii B I iii C ii iii D i ii E iii only Solute in an aqueous solution Ionic Compound Molecular Compound Acids weak bases Strong Acids Strong Electrolyte IONS Most Molecular Compounds Weak Acids Bases Weak Electrolyte MOLECULES IONS Nonelectrolyte MOLECULES Ethanol dissolves in water so does sugar oil does not Table with things that dissolve and things that don t dissolve in the book Dissolve Na K Li NH4 F A Br SO42 Exceptions Pb Hg Ag Don t dissolve CO32 PO43ConcepTest Which ionic compound containing lead is at least moderately soluble i bromide ii Sulfate iii Carbonate A i ii iii B i iii C ii iii D i ii E all are insoluble Acetic acid H AcetateConcepTest Which ionic compound containing silver is at least moderately soluble i ii iii A i ii iii Bromide soluble w exception to silver Acetate moderately soluble with silver Carbonate insoluble silver is no exception B i iii C i ii D i ii E all are insoluble Reactions related to solubility Precipitation A B aq C D aq A D C B The reactants have to be soluble Are the products soluble If they are not soluble then a precipitate forms ConcepTest Consider the reaction PbF 2 s 2 NaCl aq PbCl2 s 2NaF aq A Precipitation lead II chloride is formed B Precipitation lead II fluoride is formed C Not precipitation lead II chloride can t form neither AB or AD are soluble D Not precipitation the eqn is not balanced false Acid Base Reactions Strong acid sulfuric hydrochloric Strong base hydroxide OH w Group 1A Weak acid Weak base NH3