1. John E. McMurry Robert C. Fay C H E M I S T R Y Sixth Edition © 2012 Pearson Education, Inc. Chapter 4 Reactions in Aqueous Solution

2. Some Ways That Chemical Reactions Occur Precipitation Reactions: Processes in which soluble reactants yield an insoluble solid product that falls out of solution. 2KNO 3 (aq) + Pb I 2 (s)Pb(NO 3 ) 2 (aq) + 2K I (aq)

3. Some Ways That Chemical Reactions Occur Acid-Base Neutralization Reactions: Processes in which an acid reacts with a base to yield water plus a salt. H 2 O(l) + NaCl(aq)HCl(aq) + NaOH(aq)

4. Some Ways That Chemical Reactions Occur Oxidation-Reduction (Redox) Reactions: Processes in which one or more electrons are transferred between reaction partners (atoms, molecules, or ions). MgCl 2 (aq) + H 2 (g)Mg(s) + 2HCl(aq)

5. Electrolytes in Aqueous Solution Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 4/5 Electrolytes: Substances which dissolve in water to produce conducting solutions of ions. H2OH2O Na 1+ (aq) + Cl 1- (aq)NaCl(s) A solution of NaCl conducts electricity because of the movement of charged particles (ions).

6. Electrolytes in Aqueous Solution Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 4/6 Nonelectrolytes: Substances which do not produce ions in aqueous solutions. H2OH2O C 12 H 22 O 11 (aq)C 12 H 22 O 11 (s) A solution of C 12 H 22 O 11 does not conduct electricity because it contains no charged particles (ions).

7. Electrolytes in Aqueous Solution Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 4/7 Weak Electrolytes: Compounds that dissociate to a small extent into ions when dissolved in water. H 1+ (aq) + CH 3 CO 2 1- (aq)CH 3 CO 2 H(aq) Strong Electrolytes: Compounds that dissociate to a large extent into ions when dissolved in water. K 1+ (aq) + Cl 1- (aq)KCl(aq)

8. Electrolytes in Aqueous Solution Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 4/8 Strong Acids: hydrochloric acid, hydrobromic acid, hydroiodic acid, perchloric acid, nitric acid, sulfuric acid.

9. Electrolytes in Aqueous Solution Copyright © 2008 Pearson Prentice Hall, Inc.Chapter 4/9 Ionic Compounds

10. Electrolytes in Aqueous Solution Copyright © 2008 Pearson Prentice Hall, Inc. Chapter 4/10 Weak acids

11. Electrolytes in Aqueous Solution Copyright © 2008 Pearson Prentice Hall, Inc. Chapter 4/11 Molecular Compounds (other than any strong or weak electrolytes)

12. Aqueous Reactions and Net Ionic Equations Copyright © 2008 Pearson Prentice Hall, Inc. Chapter 4/12 2KNO 3 (aq) + Pb I 2 (s)Pb(NO 3 ) 2 (aq) + 2K I (aq) Molecular Equation: All substances in the chemical equation are written using their complete formulas as if they were molecules. strong electrolytes precipitate

13. Aqueous Reactions and Net Ionic Equations Copyright © 2008 Pearson Prentice Hall, Inc. Chapter 4/13 Ionic Equation: All of the strong electrolytes are written as ions. 2K 1+ (aq) + 2NO 3 1- (aq) + Pb I 2 (s) Pb 2+ (aq) + 2NO 3 1- (aq) + 2K 1+ (aq) + 2 I 1- (aq) 2KNO 3 (aq) Pb(NO 3 ) 2 (aq) 2K I (aq)

14. Aqueous Reactions and Net Ionic Equations Copyright © 2008 Pearson Prentice Hall, Inc. Chapter 4/14 Spectator Ions: Ions that undergo no change during the reaction and appear on both sides of the reaction arrow. 2K 1+ (aq) + 2NO 3 1- (aq) + Pb I 2 (s) Pb 2+ (aq) + 2NO 3 1- (aq) + 2K 1+ (aq) + 2 I 1- (aq)

15. Aqueous Reactions and Net Ionic Equations Copyright © 2008 Pearson Prentice Hall, Inc. Chapter 4/15 Pb I 2 (s) Pb 2+ (aq) + 2 I 1- (aq) Net Ionic Equation: Only the ions undergoing change are shown.

16. Chapter 4/16© 2012 Pearson Education, Inc. Precipitation Reactions and Solubility Guidelines

17. Inorganic Salt-Solubility RuleImportant Exceptions 1. All nitrate (NO 3 ¯), nitrite (NO 2 ¯), chlorate (ClO 3 ¯) and perchlorate (ClO 4 ¯) salts are soluble. Silver nitrite and potassium perchlorate are considered slightly soluble. 2. Essentially, all alkali metal (Li +, Na +, K +, Rb +, Cs + ) and ammonium (NH 4 + ) salts are soluble. Some Li + are insoluble. 3. Most halogen (Cl¯, Br¯, I¯) salts are soluble. Ag +, Pb 2+, Hg 2 2+, Cu +, Tl + (Pb 2+ halogens are soluble in hot water.) HgBr 2 is slightly soluble. 4. Most acetate (C 2 H 3 O 2 ¯) salts are soluble.Ag +, Hg 2 2+ 5. Most sulfate (SO 4 2 ¯) salts are soluble. Ca 2+, Sr 2+, Ba 2+, Ra 2+, Pb 2+, Ag +, Hg 2+ (Some sources consider calcium sulfate and silver sulfate to be slightly soluble.) 6. Many sulfides (S 2 ¯) are insoluble. All alkali metal and alkaline earth (Be 2+, Mg 2+, Ca 2+, Sr 2+, Ba 2+, Ra 2+ ) sulfides are soluble. Ammonium sulfide is soluble. (Some sources consider MgS, CaS and BaS to be slightly soluble.) 7. Most borates (BO 3 2 ¯), carbonates (CO 3 2 ¯), chromates (CrO 4 2 ¯), phosphates (PO 4 3 ¯), and sulfites (SO 3 2 ¯) are slightly soluble. MgCrO 4 is soluble, MgSO 3 is slightly soluble. 7. Most hydroxide (OH¯) salts are insoluble Alkali metal hydroxides are soluble. Ba 2+, Sr 2+, Ca 2+, Tl + are considered slightly soluble.

18. Precipitation Reactions and Solubility Guidelines Copyright © 2008 Pearson Prentice Hall, Inc. Chapter 4/18 Write the molecular, ionic, and net ionic equations for the reaction that occurs when aqueous solutions of AgNO 3 and Na 2 CO 3 are mixed.

19. Precipitation Reactions and Solubility Guidelines Write the chemical formulas of the products (use proper ionic rules). Ag 2 CO 3 (??)AgNO 3 (aq) + Na 2 CO 3 (aq) + NaNO 3 (??) CB + ADAB + CD double replacement reaction

20. Example Write the molecular, ionic, and net ionic equations for the reaction that occurs when aqueous solutions of FeCl 3 and Na 2 SO 4 are mixed Aqueous solution of Mg(NO 3 ) 2 and (NH 4 ) 2 S