Types of Chemical Reactions Synthesis (Combination) reaction A + B  AB Decomposition reaction AB  A + B ASingle-replacement reaction A + BC  AC + B element compound compound element BDouble-replacement reaction AB + CD  AD + CB compound compound compound compound Neutralization reaction HX + BOH  BX + HOH Objective: To classify a chemical reaction as one of the following types: combination (synthesis), decomposition, single replacement, double replacement, or neutralization. acid base salt water CH + O2  CO2 + H2O Combustion reaction (of a hydrocarbon) Polymerization Polymer = monomer + monomer + … Ause activity series to predict Bdriving force…water, gas, or precipitate

Types of Chemical Reactions Synthesis (Combination) reaction A + B  AB Decomposition reaction AB  A + B ASingle-replacement reaction A + BC  AC + B BDouble-replacement reaction AB + CD  AD + CB Neutralization reaction HX + BOH  BX + HOH CH + O2  CO2 + H2O Objective: To classify a chemical reaction as one of the following types: combination (synthesis), decomposition, single replacement, double replacement, or neutralization. Combustion reaction (of a hydrocarbon) Polymerization Polymer = monomer + monomer + … Ause activity series to predict Bdriving force…water, gas, or precipitate

Chemical Equations

Synthesis Reaction Direct combination reaction (Synthesis) 2 Na + Cl2  2 NaCl Na Na Cl Cl  Cl Cl Na Na General form: A + B  AB element or element or compound compound compound

Synthesis Reaction Direct combination reaction (Synthesis) 2 Na + Cl2  2 NaCl Na Cl Na+ Cl - Cl Cl - Na+ Na General form: A + B  AB element or element or compound compound compound

Formation of a solid: AgCl AgNO3(aq) + KCl(aq)  KNO3 (aq) + AgCl(s)

Pb2+ Cl1- K1+ I1- Pb2+ Cl1- K1+ I1- Cl2 Pb I K KCl PbI2 + + lead (II) chloride + potassium iodide potassium chloride + lead (II) iodide Pb2+ Cl1- K1+ I1- Pb2+ Cl1- K1+ I1- Cl2 Pb + I K KCl + PbI2 (aq) (ppt) A reaction that yields an insoluble product, a precipitate, when two solutions are mixed Are a subclass of exchange reactions that occur between ionic compounds when one of the products is insoluble Used to isolate metals that have been extracted from their ores and to recover precious metals for recycling Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.

Pb2+ Cl1- K1+ I1- Pb2+ Cl1- K1+ I1- Cl2 Pb I K KCl PbI2 + + A reaction that yields an insoluble product, a precipitate, when two solutions are mixed Are a subclass of exchange reactions that occur between ionic compounds when one of the products is insoluble Used to isolate metals that have been extracted from their ores and to recover precious metals for recycling lead (II) chloride + potassium iodide potassium chloride + lead (II) iodide Pb2+ Cl1- K1+ I1- Pb2+ Cl1- K1+ I1- Cl2 Pb + I K KCl + PbI2 (aq) (ppt) Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.

Decomposition Reaction 2 H2O + 2 H2 O2 H H O O H + H O O H General form: AB A + B compound two or more elements or compounds

Single and Double Replacement Reactions Single-replacement reaction Mg + CuSO4  MgSO4 + Cu General form: A + BC  AC + B Double-replacement reaction CaCO3 + 2 HCl  CaCl2 + H2CO3 General form: AB + CD  AD + CB

Activity Series Element Reactivity Halogen Reactivity Foiled again – Printable Version of Activity Series Element Reactivity Ca Li Rb K Ba Ca Na Mg Al Mn Zn Cr Fe Ni Sn Pb H2 Cu Hg Ag Pt Au Foiled again – Aluminum loses to Calcium Halogen Reactivity F2 Cl2 Br2 I2 Objectives: To explain the concept of an activity series for metals. To predict whether a single-replacement reaction occurs by referring to the activity series. The Activity Series – Predicts the outcome of the single-displacement reactions – Arranges metal and hydrogen in decreasing order of their tendency to be oxidized – Active metals at the top of the series have the greatest tendency to lose electrons; these including alkali metals (Group 1), alkaline earths (Group 2), and Al (Group 13). – Inert metals at the bottom of the series have the lowest tendency to be oxidized; these include precious metals or coinage metals located in the lower-right portion of the metals in the periodic table. – Any element will reduce compounds of the elements below it in the series. – Only those metals that lie above hydrogen in the activity series dissolve in acids to produce H2.

TABLE OF SOLUBILITIES IN WATER aluminum ss s n i d ammonium barium calcium copper (II) iron (II) iron (III) lead magnesium mercury (I) mercury (II) potassium silver sodium zinc acetate bromide carbonate chloride chromate hydroxide iodide nitrate phosphate sulfate sulfide Legend SOLID AQUEOUS i = insoluble ss = slightly soluble s = soluble d = decomposes n = not isolated

TABLE OF SOLUBILITIES IN WATER aluminum s aq n d ammonium barium calcium ss copper (II) iron (II) iron (III) lead magnesium mercury (I) si mercury (II) potassium silver sodium zinc acetate bromide carbonate chloride chromate hydroxide iodide nitrate phosphate sulfate sulfide Legend s = solid aq = aqueous d = decomposes n = not isolated

TABLE OF SOLUBILITIES IN WATER aluminum ss s n i d ammonium barium calcium copper (II) iron (II) iron (III) lead magnesium mercury (I) mercury (II) potassium silver sodium zinc acetate bromide carbonate chloride chromate hydroxide iodide nitrate phosphate sulfate sulfide Legend s = solid aq = aqueous d = decomposes n = not isolated

Solubility Rules 1. Most nitrates are soluble. Most salts containing Group I ion and ammonium ion, NH4+, are soluble. Most chloride, bromide, and iodide salts are soluble, except Ag+, Pb2+ and Hg22+. 4. Most sulfate salts are soluble, except BaSO4, PbSO4, Hg2SO4, and CaSO4. Most hydroxides except Group 1 and Ba(OH)2, Sr(OH)2, and Ca(OH)2 are only slightly soluble. Most sulfides, carbonates, chromates, and phosphates are only slightly soluble. Ohn-Sabatello, Morlan, Knoespel, Fast Track to a 5 Preparing for the AP Chemistry Examination 2006, page 91

Potassium reacts with Water P O W !

Double Replacement Reaction K2CO3 (aq) Potassium carbonate + BaCl2 (aq) Barium chloride 2 KCl (aq) Potassium chloride + BaCO3 (s) Barium carbonate

Synthesis Reactions Photosynthesis 6 CO2 + H2O C6H12O6 + O2 6 6 Formation of water 2 H2 + O2 H2O 2 Formation of salt http://www.pdphoto.org/jons/pictures2/leaf_1_bg_010503.jpg http://www.uwsp.edu/geo/faculty/ritter/images/lithosphere/mass_wasting_erosion/rain_splash_NRCS_p0000003256_small.jpg http://whyfiles.org/111salt/images/salt_magn2.jpg A photomicrograph of common table salt © Carl J. Bowser, Department of Geology and Geophysics, University of Wisconsin, Madison 2 Na + Cl2 NaCl 2 General Form A + B C

Decomposition Reactions Hydrogen Peroxide 2 H2O2 H2O + O2 2 Electrolysis of water H2O H2 + O2 electricity 2 2 Nitrogen triiodide 2 NI3 N2 + I2 3 General Form AB A + B

Predict if these reactions will occur 3 Mg + AlCl3 2 2 Al + MgCl2 3 Can magnesium replace aluminum? YES, magnesium is more reactive than aluminum. Activity Series Al + MgCl2 No reaction Can aluminum replace magnesium? NO, aluminum is less reactive than magnesium. Therefore, no reaction will occur. Activity Series Order of reactants DOES NOT determine how they react. MgCl2 + Al No reaction The question we must ask is can the single element replace its counterpart? metal replaces metal or nonmetal replaces nonmetal.

Single-Replacement Reactions Activity Series Li Rb K Ba Ca Na Mg Al Mn Zn Cr Fe Ni Sn Pb H2 Cu Hg Ag Pt Au “Magic blue-earth” Fe + CuCl2 FeCl2 + Cu Can Fe replace Cu? Yes Zinc in nitric acid F2 Cl2 Br2 I2 Zn + HNO3 Zn(NO3)2 + H2 2 Can Zn replace H? Yes NO REACTION MgBr2 + Cl2 MgCl2 + Br2 Can Br replace Cl? No General Form A + BC AC + B

KOH(aq) + HNO3(aq) KNO3(aq) + H2O ? How would you prepare potassium nitrate (using a double replacement reaction)? potassium nitrate formation of water is a driving force. K K OH KOH + HNO3 KNO3 + H2O + H H NO3 KNO3 + H2O _________ _________ _________ Ca(NO3)2 Both potassium nitrate and calcium chloride are soluble (no driving force – no reaction!) 2 KOH + Ca(NO3)2 2 KNO3 + Ca(OH)2 Combine a potassium hydroxide solution with nitric acid to yield soluble potassium nitrate. KOH(aq) + HNO3(aq) KNO3(aq) + H2O ? The water could then be removed by distillation to recover solid potassium nitrate.

Fe2+ Cl1- Na1+ CO32- Fe2+ Cl1- Na1+ CO32- Cl2 Fe CO3 Na2 NaCl FeCO3 Predict if a reaction will occur when you combine aqueous solutions of iron (II) chloride with aqueous sodium carbonate solution. If the reaction does occur, write a balanced chemical equation showing it. (be sure to include phase notation) Balanced chemical equation iron (II) chloride + sodium carbonate sodium chloride + iron (II) carbonate Fe2+ Cl1- Na1+ CO32- Fe2+ Cl1- Na1+ CO32- Cl2 Fe CO3 Na2 NaCl FeCO3 (aq) (ppt) Using a SOLUBILITY TABLE: sodium chloride is soluble iron (II) carbonate is insoluble FeCl2 Na2CO3 NaCl FeCO3 (aq) (ppt) + 2 (aq) (aq) Complete Ionic Equation Fe2+(aq) + 2Cl1-(aq) + 2Na1+(aq) + CO32-(aq) 2Na1+(aq) + 2Cl1-(aq) + FeCO3(s)