2Water is the "universal solvent" IntroductionMany reactions involve substances dissolved in water.When this happens, solutions formSolutions (homogeneous substances)Two parts:SOLUTES- substances dissolved in waterSOLVENTS- the most plentiful substance in a solutionWater is the "universal solvent"
3Water, the universal solvent (H2O) Examples of Solutes:Molecular compounds that exist as moleculesMolecular compounds that form ions when they dissolve in water (H+ ions=acids)Ionic compoundsWhen dissolved in water, the ions can separate
4The ProductsWhen 2 aqueous solutions that contain ions are combined, the ions may react with one another in a DOUBLE-REPLACEMENT reaction producing:A. Precipitate (s)B. Water (l)C. Gas (g)
5A. PrecipitateUse ionic equations to show the details of reactions that involve ions in aqueous solutionsSubstances are written as ionsComplete ionic equations- show all particles involved in a chemical reaction
7Spectator IonsNotice, that there are ions that appear on both sides of the equationThese ions do not participate in the formation of the solid productThese ions are called spectator ions.What were the spectator ions in the previous slide?
8Net Ionic EquationsEquations that show only the ions involved- omitting the spectator ions are called complete ionic equations!From the previous example:Cl- + Ag+ AgCl (s)
9Practice!Write the chemical, balanced, complete ionic and net ionic equation for the following:Aqueous solutions of potassium iodide and silver nitrate are mixed, forming the precipitate silver iodide.See white board for solution!
10B. Water Some reactions form water No evidence of the chemical reaction can be observed. Why?Example:HCl (aq) + KOH (aq) H2O (l) + KCl (aq)H+ (aq) + OH- (aq) H2O (l)
11Practice!Sulfuric acid (H2SO4) and aqueous potassium hydroxide react to produce water and potassium sulfate.