1. 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

2. Ca Printable Version of Activity Series Activity Series Element Reactivity 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

3. Activity Series of the elements • Activity series – list of elements organized according to the ease with which the elements undergo certain chemical reactions. • Used to predict if a reaction will take place • For metals – greater activity means loss of electrons • For nonmetals – greater activity means ease to gain electrons

4. Order of listing is usually determined by single-replacement reactions • Most active element is placed at the top of the series • An element can replace any element below it on the series • An element cannot replace any element above it on the series

5. Double Replacement Double replacement – ions of two compounds exchange places in an aqueous solution to form two new compounds AX + BY AY + BX FeS + 2HCl H2S + FeCl2

6. Types of Double Replacement Reactions • Formation of a precipitate • Formation of a gas 3. Formation of water

7. Potassium reacts with Water P O W !

8. Predict if these reactions will occur Al + MgCl2 3 2 2 3 Mg + AlCl3 Can magnesium replace aluminum? YES, magnesium is more reactive than aluminum. Activity Series No reaction Al + MgCl2 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. No reaction MgCl2 + Al The question we must ask is can the single element replace its counterpart? metal replaces metal or nonmetal replaces nonmetal.

9. A + BC AC + B 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” FeCl2 + Cu Fe + CuCl2 Yes Can Fe replace Cu? Zinc in nitric acid F2 Cl2 Br2 I2 2 Zn + HNO3 Zn(NO3)2 + H2 Yes Can Zn replace H? NO REACTION MgBr2 + Cl2 MgCl2 + Br2 No Can Br replace Cl? General Form

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

11. chromate hydroxide carbonate bromide chloride sulfide sulfate nitrate phosphate iodide acetate Legend s = solid aq = aqueous d = decomposes n = not isolated

12. 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 Examination2006, page 91

13. Find the precipitate • HCl(aq) + AgNO3(aq)  HNO3( ) + AgCl( ) • 3 CaCl2(aq) + 2 Na3PO4(aq)  Ca3(PO4)2( ) + 6 NaCl( ) • Pb(NO3)2(aq ) + BaCl2( aq )  PbCl2() + Ba(NO3)2( ) • FeCl3(aq) + 3 NaOH(aq)  Fe(OH)3( ) + 3 NaCl( ) • H2SO4(aq) + Ca(OH)2(aq)  2 H2O( ) + CaSO4( ) • 2 KOH(aq) + CuSO4(aq)  K2SO4( ) + Cu(OH)2( )

14. Predict if these reactions will occur HCl(aq) + Pb(NO3)2(aq)  Don’t forget to balance the equation 2 HNO3() 2 + PbCl2( ) aq ? S ? Will a precipitate form? Yes, so the reaction will take place. Ca(OH)2( ) NH4OH(aq) + CaSO4(aq)  (NH4)2SO4() + No reaction aq aq ? ? Will a precipitate form? No, so the reaction will not take place.