1. Reactions in Aqueous Solution Chapter 4 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Big Ideas from 4.1-4.2 Do substances dissolved in water exist as ions, molecules, or a mixture of the two? When do precipitates form when two solutions are mixed?

2. Tuesday, March 22 Do Now 1.Notecard check 2.Questions about the terms 3.A 0.1 M solution of acetic acid (CH 3 COOH) causes the lightbulb in the apparatus of Figure 4.2 to glow about as brightly as a 0.001 M solution of HBr. How do you account for this fact?

3. 4.1 A ___Solution_______ is a homogenous mixture of 2 or more substances The __Solute________ is(are) the substance(s) present in the smaller amount(s) The __Solvent_____ is the substance present in the larger amount SolutionSolventSolute(s) Soft drink (l) Air (g) Soft Solder (s) H2OH2O N2N2 Pb Sugar, CO 2 O 2, Ar, CH 4 Sn

4. An _electrolyte__________ is a substance that, when dissolved in water, results in a solution that can conduct electricity. A __nonelectrolyte___________ is a substance that, when dissolved, results in a solution that does not conduct electricity. _nonelectrolyte__ _weak electrolyte_ __strong electrolyte_ 4.1

5. Strong Electrolyte – __100__% dissociation NaCl (s) Na + (aq) + Cl - (aq) H2OH2O Weak Electrolyte – _chemical equilibrium_____ CH 3 COOH CH 3 COO - (aq) + H + (aq) Conduct electricity in solution? _cations__ (+) and _anions___(-) 4.1

6. _solvation_____ is the process in which an ion is surrounded by water molecules arranged in a specific manner.   H2OH2O

7. __Glucose______ does not conduct electricity No cations (+) and anions (-) in solution 4.1 C 6 H 12 O 6 (s) C 6 H 12 O 6 (aq) H2OH2O Strong Electrolytes Weak ElectrolytesNonelectrolytes HClCH 3 COOH(NH 2 ) 2 CO HNO 3 HFCH 3 OH HClO 4 HNO 2 C 2 H 5 OH NaOHH2OH2OC 12 H 22 O 11 Ionic CompoundsWeak AcidsCovalent Molecules

8. Practice Problems Pg 156, 4.11 – 4.17

9. Check for Understanding What dissolved species are present in a solution of a) KCN, b) NaClO 4 ? Which solute will cause a lightbulb to glow more brightly, CH 3 OH or MgBr 2 ?

10. Wednesday March 23 Do Now What dissolved species are present in a solution of AgNO 3 ? Of Al 2 (SO 4 ) 3 ? Goal for today: I can write molecular equations, complete ionic equations, and net ionic equations. I can predict whether or not a precipitate will form in solution.

11. Notecard Notes Molecular Compounds dissolved in water –HCl Chemical Equilibrium – going between ions and original substance (HCl not an example)

12. Precipitation Reactions __Precipitate_ –insoluble solid that separates from solution _Molecular Equation_____ _Complete Ionic Equation_______ _Net Ionic Equation_______ Pb 2+ + 2NO 3 - + 2Na + + 2I - PbI 2 (s) + 2Na + + 2NO 3 - Na + and NO 3 - are _spectator_____ ions PbI 2 Pb(NO 3 ) 2 (aq) + 2NaI (aq) PbI 2 (s) + 2NaNO 3 (aq) precipitate Pb 2+ + 2I - PbI 2 (s) 4.2

13. Writing Net Ionic Equations 1.Write the balanced molecular equation. 2.Write the ionic equation showing the strong electrolytes 3.Determine precipitate from solubility rules 4.Cancel the spectator ions on both sides of the ionic equation AgNO 3 (aq) + NaCl (aq) AgCl (s) + NaNO 3 (aq) 4.2 Write the net ionic equation for the reaction of silver nitrate with sodium chloride.

14. Solubility Rules for Common Ionic Compounds In water at 25 0 C 4.2 Memorize! 1.All compounds containing alkali metal cations and the ammonium ion (NH 4 +1 ) are soluble. 2.All compounds containing NO 3 -, ClO 4 - (perchlorate), ClO 3 - (chlorate), and C 2 H 3 O 2 - (acetate) anions are soluble. 3.All chlorides, bromides, and iodides are soluble except those containing Ag +, Pb 2+, or Hg 2+. 4.All sulfates (SO 4 -2 ) are soluble except those containing Hg 2+, Pb 2+, Sr 2+, Ca 2+, or Ba 2+. 5.All hydroxides (OH -1 ) are insoluble except compounds of the alkali metals, Ca 2+, Sr 2+, and Ba 2+. 6.All compounds containing PO 4 3- (phosphate), S 2- (sulfide), CO 3 2- (carbonate), and SO 3 2- (sulfite) ions are insoluble except those that also contain alkali metals or NH 4 +.

15. Predict Write out the net ionic equation for the reaction between AgNO 3 and KI. Will a precipitate form? Write out the net ionic equation for the reaction between Ca(OH) 2 and SrCl 2. Will a precipitate form?

16. Practice Problems Pg 157 4.20, 4.21, 4.23, 4.25, 4.26, 4.28

17. Thursday, March 24 th Do Now Using the following reactants, write out the net ionic equation: Sr(NO 3 ) 2(aq) + H 2 SO 4(aq)  Goals: I can define and identify substances as acids or bases.

18. Acids Have a sour taste. Vinegar owes its taste to acetic acid. Citrus fruits contain citric acid. React with certain metals to produce hydrogen gas. React with carbonates and bicarbonates to produce carbon dioxide gas Have a bitter taste. Feel slippery. Many soaps contain bases. Bases 4.3

19. Arrhenius_ acid is a substance that produces H + (H 3 O + ) in water _ Arrhenius __ base is a substance that produces OH - in water 4.3

20. A _Bronsted____ acid is a proton donor A _Bronsted____ base is a proton acceptor acidbaseacidbase 4.3 A _Bronsted_ acid must contain at least one ionizable proton!

21. Monoprotic___ acids HCl H + + Cl - HNO 3 H + + NO 3 - CH 3 COOH H + + CH 3 COO - Strong electrolyte, strong acid Weak electrolyte, weak acid _Diprotic____ acids H 2 SO 4 H + + HSO 4 - HSO 4 - H + + SO 4 2- Strong electrolyte, strong acid Weak electrolyte, weak acid __Triprotic___ acids H 3 PO 4 H + + H 2 PO 4 - H 2 PO 4 - H + + HPO 4 2- HPO 4 2- H + + PO 4 3- Weak electrolyte, weak acid 4.3

22. _Neutralization____ Reaction acid + base _water__ + __salt__ + _energy_ All _salts/neutralized solutions are strong electrolytes. HCl (aq) + NaOH (aq) NaCl (aq) + H 2 O H + + Cl - + Na + + OH - Na + + Cl - + H 2 O H + + OH - H 2 O 4.3

23. Practice Problems Pg 157 4.20, 4.21, 4.23, 4.25, 4.26, 4.28 Problem Set #1 due tomorrow!!!! Solubility Rules Quiz on Monday. 10 pts extra credit on the quiz for a catchy way of remembering the rules.

24. Oxidation-Reduction Reactions (electron transfer reactions) 2Mg (s) + O 2 (g) 2MgO (s) 2Mg 2Mg 2+ + 4e - O 2 + 4e - 2O 2- ________ half-reaction (lose e - ) ________ half-reaction (gain e - ) 2Mg + O 2 + 4e - 2Mg 2+ + 2O 2- + 4e - 2Mg + O 2 2MgO 4.4

25. Zn (s) + CuSO 4 (aq) ZnSO 4 (aq) + Cu (s) Zn is ________Zn Zn 2+ + 2e - Cu 2+ is _______Cu 2+ + 2e - Cu Zn is the ________ agent Cu 2+ is the _______ agent 4.4

26. Copper wire reacts with silver nitrate to form silver metal. What is the oxidizing agent in the reaction? Cu (s) + 2AgNO 3 (aq) Cu(NO 3 ) 2 (aq) + Ag (s) Cu Cu 2+ + 2e - Ag + + 1e - AgAg + is ________Ag + is the _____________

27. Oxidation number The charge the atom would have in a molecule (or an ionic compound) if electrons were completely transferred. 1.Free elements (uncombined state) have an oxidation number of zero. Na, Be, K, Pb, H 2, O 2, P 4 = 0 2.In monatomic ions, the oxidation number is equal to the charge on the ion. Li +, Li = +1; Fe 3+, Fe = +3; O 2-, O = -2 3.The oxidation number of oxygen is usually –2. In H 2 O 2 and O 2 2- it is –1. 4.4

28. 4.The oxidation number of hydrogen is +1 except when it is bonded to metals in binary compounds. In these cases, its oxidation number is –1. 6. The sum of the oxidation numbers of all the atoms in a molecule or ion is equal to the charge on the molecule or ion. 5.Group IA metals are +1, IIA metals are +2 and fluorine is always –1. HCO 3 - O =H = 3x-2 + 1 + ? = -1 C = Oxidation numbers of all the atoms in HCO 3 - ? 4.4

29. NaIO 3 Na = O = 3x-2 + 1 + ? = 0 I = IF 7 F = 7x-1 + ? = 0 I = K 2 Cr 2 O 7 O =K = 7x-2 + 2x+1 + 2x? = 0 Cr = Oxidation numbers of all the atoms in the following ? 4.4

30. Types of Oxidation-Reduction Reactions Reaction A + B C S + O 2 SO 2 Reaction 2KClO 3 2KCl + 3O 2 C A + B 00 +4-2 +1+5-2+10 4.4

31. Reaction A + BC AC + B Sr + 2H 2 O Sr(OH) 2 + H 2 TiCl 4 + 2Mg Ti + 2MgCl 2 Cl 2 + 2KBr 2KCl + Br 2 Hydrogen Displacement Metal Displacement Halogen Displacement Types of Oxidation-Reduction Reactions 4.4 0 +1+20 0+40+2 0 0

32. The Activity Series for Metals M + BC AC + B Displacement Reaction M is metal BC is acid or H 2 O B is H 2 Ca + 2H 2 O Ca(OH) 2 + H 2 Pb + 2H 2 O Pb(OH) 2 + H 2 4.4

33. Reaction Cl 2 + 2OH - ClO - + Cl - + H 2 O Element is simultaneously oxidized and reduced. Types of Oxidation-Reduction Reactions Chlorine Chemistry 0 +1 4.4

34. Ca 2+ + CO 3 2- CaCO 3 NH 3 + H + NH 4 + Zn + 2HCl ZnCl 2 + H 2 Ca + F 2 CaF 2 __________________ Classify the following reactions. 4.4

35. Solution Stoichiometry The ________________ of a solution is the amount of solute present in a given quantity of solvent or solution. M = ____________ = moles of solute liters of solution 4.5

36. Solution Stoichiometry What mass of KI is required to make 500 mL of a 2.80 M KI solution? volume KImoles KIgrams KI M KI 500 mL= _____ g KI 166 g KI 1 mol KI x 2.8 mol KI 1 L soln x 1 L 1000 mL x 4.5

38. ________________ is the procedure of preparing a less concentrated solution from a more concentrated solution. Dilution Add Solvent Moles of solute before dilution (i) Moles of solute after dilution (f) = MiViMiVi MfVfMfVf = 4.5

39. How would you prepare 60.0 mL of 0.200 M HNO 3 from a stock solution of 4.00 M HNO 3 ? M i V i = M f V f M i = 4.00 M f = 0.200V f = 0.06 L V i = ? L 4.5 V i = MfVfMfVf MiMi = =

40. Gravimetric Analysis 4.6 1.Dissolve unknown substance in water 2.React unknown with known substance to form a precipitate 3.Filter and dry precipitate 4.Weigh precipitate 5.Use chemical formula and mass of precipitate to determine amount of unknown ion

41. ___________________ In a _____________________ a solution of accurately known concentration is added gradually added to another solution of unknown concentration until the chemical reaction between the two solutions is complete. ________________ – the point at which the reaction is complete _______________ – substance that changes color at (or near) the equivalence point Slowly add base to unknown acid UNTIL The indicator changes color (pink) 4.7

42. What volume of a 1.420 M NaOH solution is required to titrate 25.00 mL of a 4.50 M H 2 SO 4 solution? 4.7 BALANCE THE CHEMICAL EQUATION! volume acidmoles acidmoles basevolume base H 2 SO 4 + NaOH H 2 O + Na 2 SO 4 M acid rx coef. M base

43. What volume of a 1.420 M NaOH solution is Required to titrate 25.00 mL of a 4.50 M H 2 SO 4 solution? 4.7 BALANCE THE CHEMICAL EQUATION! volume acidmoles acidmoles basevolume base H 2 SO 4 + 2NaOH 2H 2 O + Na 2 SO 4 4.50 mol H 2 SO 4 1000 mL soln x 2 mol NaOH 1 mol H 2 SO 4 x 1000 ml soln 1.420 mol NaOH x 25 mL = _____ mL M acid rx coef. M base

44. (4.72 p.120) What volume of a 0.500 M KOH solution is required to titrate 10.0 mL of a 0.20 M H 2 SO 4 solution? 4.7 volume acidmoles acidmoles basevolume base H 2 SO 4 + KOH H 2 O + K 2 SO 4 ___ mol H 2 SO 4 ____ mL soln x __ mol KOH __ mol H 2 SO 4 x ____ ml soln ____ mol KOH x 10.0 mL = ___ mL M acid rx coef. M base

45. (4.72 p.120) What volume of a 0.500 M KOH solution is required to titrate 10.00 mL of a 0.20 M H 2 SO 4 solution? 4.7 volume acidmoles acidmoles basevolume base H 2 SO 4 + 2KOH 2H 2 O + Na 2 SO 4 0.20 mol H 2 SO 4 1000 mL soln x 2 mol KOH 1 mol H 2 SO 4 x 1000 ml soln 0.500 mol KOH x 10.0 mL = _____ mL M acid rx coef. M base