Types of Chemical Reactions 6.2 Assigning oxidation numbers for individual atoms of monatomic and polyatomic ions 6.3 Identifying the nomenclature of ionic compounds, binary compounds, and acids 6.4 Classifying chemical reactions as composition, decomposition, single replacement, or double replacement AHSGE Reading 4.2 Demonstrate the ability to preview and predict. Other AOD C.6.1 Define stoichiometry, reactants, and products.

What are some types of chemical reactions? 1.Synthesis 2.Decompostion 3.Single Replacement/Single Displacement 4.Double Replacement/Double Displacement 5.Combustion  Complete combustion yields ________.  Incomplete combustion yields __________.

“Classes” of Reactions 1.Precipitation reactions 2.Acid-base reactions 3.Oxidation-reduction reactions  Almost all reaction types can be put into one of these three “classes”.

Precipitation Reactions  What do you think this reaction would involve?  AKA, double replacement/double displacement  Example: K 2 CrO 4 (aq) + Ba(NO 3 ) 2 (aq) → ???  What does (aq) mean?  What are some other designations?  What is the name of K 2 CrO 4 ? Ba(NO 3 ) 2 ?  What would the products be in a double displacement reaction?  Would either product be a solid (precipitate)?

Three Ways to Write the Reaction Equation 1.Molecular equation: shows the overall balanced reaction (reactants and products) 2.Complete ionic equation: shows a balanced equation of the actual FORMS of the reactants and products in the reaction 3.Net ionic equation: balanced equation showing ONLY the ions involved in the reaction.  Ions that remain in solution (as ions) are not shown. (“spectator ions”)

K 2 CrO 4 (aq) + Ba(NO 3 ) 2 (aq) → ??? 1.Molecular equation: K 2 CrO 4 (aq) + Ba(NO 3 ) 2 (aq) → 2 KNO 3 (aq) + BaCrO 4 (s) 2.Complete ionic equation: 2K + (aq) + CrO 4 2- (aq) + Ba 2+ (aq) + 2NO 3 - (aq) → BaCrO 4 (s) + 2K + (aq) + 2NO 3 - (aq) 3.Net ionic equation:  What is the only CHANGE in this rxn?  CrO 4 2- (aq) + Ba 2+ (aq) → BaCrO 4 (s)

Examples  See Sample Exercise 4.9, p.155.  P. 182 (29a):  BaCl 2 (aq) + Na 2 SO 4 (aq) → BaSO 4 (s) + 2NaCl(aq)  Net ionic equation: Ba 2+ (aq) + SO 4 2- (aq) → BaSO 4 (s)  What happened to the “Cl 2 ” and the “Na 2 ” part of the molecular equation?  What would the complete ionic equation look like?

Assignment  P.182: 30, 34, 36  Special note on #34: You are MAKING UP a chemical reaction that will produce the specified solid.  It should be a precipitation (double displacement) reaction.