1. CHEM 1405: Introductory Chemistry Houston Community College Dr. Laura Jakubowski Chapter 7 – Chemical Reactions Textbook “Introductory Chemistry: Concepts and Critical Thinking” Seventh Edition by Charles H. Corwin © 2014 Pearson Education, Inc.

2. Evidence for Chemical Reactions In a physical change, the chemical composition of the substance remains constant (ice melting or boiling is a physical change) In a chemical change, the chemical composition of the substance does NOT remain constant – a chemical reaction has taken place The following indicate a chemical change: a gas is produced an insoluble solid is produced in a solution a permanent color change is observed an energy change is observed 2 © 2014 Pearson Education, Inc.

3. Evidence for Chemical Reactions A gas is produced – a reaction occurs which produces a gas as a product, typically seen as bubbles in a solution For example, mixing NaHCO 3 (s) with HC 2 H 3 O 2 (aq) produces CO 2 (g) 3 See video: http://www.youtube.com/watch?v=i_XMkTO65fo

4. Evidence for Chemical Reactions An insoluble solid is produced in a solution – two aqueous solutions are added to give an insoluble solid (called a precipitate) For example, mixing the clear, aqueous solutions of NaCl(aq) with AgNO 3 (aq) produces a white precipitate, AgCl(s) 4 See video: http://www.youtube.com/watch?v=eGG3EI4mwok

5. Evidence for Chemical Reactions A permanent color change is observed – many reactions involve a permanent color change, acid/base indicators are a good example For example, KMnO 4 (aq) reacts with a special solution to give several color changes 5 See video: http://www.youtube.com/watch?v=kKlXe2mrnHQ

6. Evidence for Chemical Reactions An energy change is observed – all reactions involve changes in energy, exothermic reactions release heat and endothermic reactions absorb heat For example, a gummy bear reacting with molten KClO 3 ( l ) is exothermic – both heat and light are given off 6 See video: http://www.youtube.com/watch?v=xJf0o9TNNXI

7. Writing Chemical Equations Formulas and symbols are used to describe a chemical reaction as a chemical equation A and B are reactants and C and D are products Physical state is abbreviated by either (s), ( l ), (g), or (aq) A catalyst is a substance that speeds up a reaction without being consumed or permanently altered (typically written above the arrow) 7 © 2014 Pearson Education, Inc. A + B  C + D

8. Writing Chemical Equations The following elements occur naturally as diatomic molecules, and should be written as such in a chemical equation 8 © 2014 Pearson Education, Inc.

9. Writing Chemical Equations Write a chemical equation for each of the following chemical reactions: mercury liquid and fluorine gas react to give solid mercury(II) fluoride zinc metal reacts with sulfuric acid to give aqueous zinc sulfate and hydrogen gas aqueous solutions of sodium iodide and silver nitrate yield silver iodide precipitate and aqueous sodium nitrate acetic acid reacts with aqueous potassium hydroxide to give aqueous potassium acetate plus water 9 © 2014 Pearson Education, Inc.

10. Writing Chemical Equations Write a chemical equation for each of the following chemical reactions: mercury liquid and fluorine gas react to give solid mercury(II) fluoride Hg( l ) + F 2 (g)  HgF 2 (s) zinc metal reacts with sulfuric acid to give aqueous zinc sulfate and hydrogen gas Zn(s) + H 2 SO 4 (aq)  ZnSO 4 (aq) + H 2 (g) aqueous solutions of sodium iodide and silver nitrate yield silver iodide precipitate and aqueous sodium nitrate NaI(aq) + AgNO 3 (aq)  AgI(s) + NaNO 3 (aq) acetic acid reacts with aqueous potassium hydroxide to give aqueous potassium acetate plus water HC 2 H 3 O 2 (aq) + KOH(aq)  KC 2 H 3 O 2 (aq) + H 2 O( l ) 10 © 2014 Pearson Education, Inc.

11. Balancing Chemical Equations It often happens that the number of atoms of each element in the reactants and products is not the same – it is therefore necessary to balance the number of atoms using whole number coefficients A coefficient multiplies all subscripts in the chemical formula 3 H 2 O has six H atoms and three O atoms For example: H 2 (g) + Cl 2 (g)  HCl(g) NOT Balanced! H 2 (g) + Cl 2 (g)  2 HCl(g) Balanced! 11 © 2014 Pearson Education, Inc. HH Cl H HH H H H H H 2 Cl 2

12. Balancing Chemical Equations Aluminum is heated with oxygen gas to give solid aluminum oxide NOT Balanced: Al(s) + O 2 (g)  Al 2 O 3 (s) Balanced: 4 Al(s) + 3 O 2 (g)  2 Al 2 O 3 (s) 12 © 2014 Pearson Education, Inc. Al O O O O O O O O O O O O O O O O O

13. Guidelines for Balancing Chemical Equations 1.Verify the formula of each substance for correct subscripts – NEVER change subscripts to balance an equation 2.Balance elements by placing a coefficient in front of each substance a)Begin balancing by starting with the most complex formula b)Balance polyatomic ions as a single unit, unless the polyatomic ion breaks down during the reaction (then atoms should be balanced separately) c)Coefficients MUST be whole numbers 3.After balancing the equation, check (√) each symbol of every element (or polyatomic ion) to verify that the coefficients are correct and finally, check the coefficients to make sure they represent the smallest whole number ratio ALL equations can be balanced – if you have trouble, check step 1 again 13 © 2014 Pearson Education, Inc.

14. Balance the Chemical Equations Aqueous solutions of lead(II) nitrate and potassium iodide produce a yellow precipitate of lead(II) iodide and an aqueous solution of potassium nitrate Aqueous solutions of calcium nitrate and sodium carbonate react to give a white precipitate of calcium carbonate and aqueous sodium nitrate Aqueous solutions of aluminum sulfate and barium nitrate react to yield a white precipitate of barium sulfate and aqueous aluminum nitrate 14 © 2014 Pearson Education, Inc. Pb(NO 3 ) 2 (aq) + KI(aq)  PbI 2 (s) + KNO 3 (aq) Ca(NO 3 ) 2 (aq) + Na 2 CO 3 (aq)  CaCO 3 (s) + NaNO 3 (aq) Al 2 (SO 4 ) 3 (aq) + Ba(NO 3 ) 2 (aq)  BaSO 4 (s) + Al(NO 3 ) 3 (aq)

15. Balance the Chemical Equations Aqueous solutions of lead(II) nitrate and potassium iodide produce a yellow precipitate of lead(II) iodide and an aqueous solution of potassium nitrate Aqueous solutions of calcium nitrate and sodium carbonate react to give a white precipitate of calcium carbonate and aqueous sodium nitrate Aqueous solutions of aluminum sulfate and barium nitrate react to yield a white precipitate of barium sulfate and aqueous aluminum nitrate 15 © 2014 Pearson Education, Inc. Pb(NO 3 ) 2 (aq) + KI(aq)  PbI 2 (s) + KNO 3 (aq) Pb(NO 3 ) 2 (aq) + 2 KI(aq)  PbI 2 (s) + 2 KNO 3 (aq) Ca(NO 3 ) 2 (aq) + Na 2 CO 3 (aq)  CaCO 3 (s) + NaNO 3 (aq) Ca(NO 3 ) 2 (aq) + Na 2 CO 3 (aq)  CaCO 3 (s) + 2 NaNO 3 (aq) Al 2 (SO 4 ) 3 (aq) + Ba(NO 3 ) 2 (aq)  BaSO 4 (s) + Al(NO 3 ) 3 (aq) Al 2 (SO 4 ) 3 (aq) + 3 Ba(NO 3 ) 2 (aq)  3 BaSO 4 (s) + 2 Al(NO 3 ) 3 (aq)

16. Balance the Chemical Equations Sulfuric acid reacts with aqueous sodium hydroxide to give aqueous sodium sulfate and water Nitric acid reacts with aqueous barium hydroxide to give aqueous barium nitrate and water Phosphoric acid reacts with solid manganese(II) hydroxide to give solid manganese(II) phosphate and water 16 © 2014 Pearson Education, Inc. H 2 SO 4 (aq) + NaOH(aq)  Na 2 SO 4 (aq) + HOH( l ) HNO 3 (aq) + Ba(OH) 2 (aq)  Ba(NO 3 ) 2 (aq) + HOH( l ) H 3 PO 4 (aq) + Mn(OH) 2 (s)  Mn 3 (PO 4 ) 2 (s) + HOH( l )

17. Balance the Chemical Equations Sulfuric acid reacts with aqueous sodium hydroxide to give aqueous sodium sulfate and water Nitric acid reacts with aqueous barium hydroxide to give aqueous barium nitrate and water Phosphoric acid reacts with solid manganese(II) hydroxide to give solid manganese(II) phosphate and water 17 © 2014 Pearson Education, Inc. H 2 SO 4 (aq) + NaOH(aq)  Na 2 SO 4 (aq) + HOH( l ) H 2 SO 4 (aq) + 2 NaOH(aq)  Na 2 SO 4 (aq) + 2 HOH( l ) HNO 3 (aq) + Ba(OH) 2 (aq)  Ba(NO 3 ) 2 (aq) + HOH( l ) 2 HNO 3 (aq) + Ba(OH) 2 (aq)  Ba(NO 3 ) 2 (aq) + 2 HOH( l ) H 3 PO 4 (aq) + Mn(OH) 2 (s)  Mn 3 (PO 4 ) 2 (s) + HOH( l ) 2 H 3 PO 4 (aq) + 3 Mn(OH) 2 (s)  Mn 3 (PO 4 ) 2 (s) + 6 HOH( l )

18. Classifying Chemical Reactions In this chapter, we study five simple types of chemical reactions: 1. Combination reaction - simple compounds combine to a more complex compound 2. Decomposition reaction - single compound broken down to simpler compounds 3. Single-replacement reaction - more reactive element displaces another 4. Double-replacement reaction - two compounds exchange anions 5. Neutralization reaction - an acid and base react to form a salt and water 18 © 2014 Pearson Education, Inc. A + Z  AZ AZ  A + Z A + BZ  AZ + B AX + BZ  AZ + BX HX + BOH  BX + HOH

19. Classifying Chemical Reactions Classify each of the following reactions: 19 © 2014 Pearson Education, Inc. Zn(s) + CuSO 4 (aq) ZnSO 4 (aq) + Cu(s) 2 Sr(s) + O 2 (g) 2 SrO(s) HC 2 H 3 O 2 (aq) + NaOH(aq) NaC 2 H 3 O 2 (aq) + HOH( l ) AgNO 3 (aq) + KCl(aq) AgCl(s) + KNO 3 (aq) Cd(HCO 3 ) 2 (s) CdCO 3 (s) + HOH(g) + CO 2 (g) ∆

20. Classifying Chemical Reactions Classify each of the following reactions: single-replacement reaction combination reaction decomposition reaction neutralization reaction double-replacement reaction 20 © 2014 Pearson Education, Inc. Zn(s) + CuSO 4 (aq) ZnSO 4 (aq) + Cu(s) 2 Sr(s) + O 2 (g) 2 SrO(s) HC 2 H 3 O 2 (aq) + NaOH(aq) NaC 2 H 3 O 2 (aq) + HOH( l ) AgNO 3 (aq) + KCl(aq) AgCl(s) + KNO 3 (aq) Cd(HCO 3 ) 2 (s) CdCO 3 (s) + HOH(g) + CO 2 (g) ∆

21. Classifying Chemical Reactions Write balanced reactions and classify each of the following: Copper metal heated with oxygen gas produces solid copper(II) oxide Heating powdered iron(III) carbonate produces solid iron(III) oxide and carbon dioxide gas Aluminum metal reacts with aqueous manganese(II) sulfate to give aqueous aluminum sulfate and manganese metal 21 © 2014 Pearson Education, Inc.

22. Classifying Chemical Reactions Write balanced reactions and classify each of the following: Copper metal heated with oxygen gas produces solid copper(II) oxide Heating powdered iron(III) carbonate produces solid iron(III) oxide and carbon dioxide gas Aluminum metal reacts with aqueous manganese(II) sulfate to give aqueous aluminum sulfate and manganese metal 22 © 2014 Pearson Education, Inc. 2 Cu(s) + O 2 (g) 2 CuO(s) combination reaction ∆ Fe 2 (CO 3 ) 3 (s) Fe 2 O 3 (s) + 3 CO 2 (g) decomposition reaction ∆ 2 Al(s) + 3 MnSO 4 (aq) Al 2 (SO 4 ) 3 (aq) + 3 Mn(s) single-replacement reaction

23. Classifying Chemical Reactions Write balanced reactions and classify each of the following: Aqueous sodium chromate reacts with aqueous barium chloride to give insoluble barium chromate and aqueous sodium chloride Nitric acid reacts with aqueous potassium hydroxide to give aqueous potassium nitrate and water 23 © 2014 Pearson Education, Inc.

24. Classifying Chemical Reactions Write balanced reactions and classify each of the following: Aqueous sodium chromate reacts with aqueous barium chloride to give insoluble barium chromate and aqueous sodium chloride Nitric acid reacts with aqueous potassium hydroxide to give aqueous potassium nitrate and water 24 © 2014 Pearson Education, Inc. Na 2 CrO 4 (aq) + BaCl 2 (aq) BaCrO 4 (s) + NaCl(aq) double-replacement reaction HNO 3 (aq) + KOH(aq) KNO 3 (aq) + HOH( l ) neutralization reaction

25. Combination reactions Metal and oxygen gas metal + oxygen gas  metal oxide 2 Mg(s) + O 2 (g) 2 MgO(s) Write a balanced chemical equation for each of the following: Zinc metal is heated with oxygen gas in the air to give solid zinc oxide Cobalt metal is heated with oxygen gas to yield solid cobalt(III) oxide 25 © 2014 Pearson Education, Inc. ∆

26. Combination reactions Metal and oxygen gas metal + oxygen gas  metal oxide 2 Mg(s) + O 2 (g) 2 MgO(s) Write a balanced chemical equation for each of the following: Zinc metal is heated with oxygen gas in the air to give solid zinc oxide Cobalt metal is heated with oxygen gas to yield solid cobalt(III) oxide 26 © 2014 Pearson Education, Inc. ∆ ∆ 2 Zn(s) + O 2 (g) 2 ZnO(s) ∆ 4 Co(s) + 3 O 2 (g) 2 Co 2 O 3 (s)

27. Metal and Oxygen Gas 27 See video: http://www.youtube.com/watch?v=5UJTR-LA1z4 ∆ 2 Mg(s) + O 2 (g) 2 MgO(s)

28. Combination Reactions Nonmetal and oxygen gas nonmetal + oxygen gas  nonmetal oxide S(s) + O 2 (g) SO 2 (g) *Several products often possible (NO, NO 2, N 2 O, N 2 O 3, N 2 O 4, N 2 O 5 ) Write a balanced chemical equation for each of the following: Phosphorus and oxygen gas react to give solid diphosphorus pentaoxide Chlorine gas is heated with oxygen to give dichlorine monoxide gas 28 © 2014 Pearson Education, Inc. ∆

29. Combination Reactions Nonmetal and oxygen gas nonmetal + oxygen gas  nonmetal oxide S(s) + O 2 (g) SO 2 (g) *Several products often possible (NO, NO 2, N 2 O, N 2 O 3, N 2 O 4, N 2 O 5 ) Write a balanced chemical equation for each of the following: Phosphorus and oxygen gas react to give solid diphosphorus pentaoxide Chlorine gas is heated with oxygen to give dichlorine monoxide gas 29 © 2014 Pearson Education, Inc. ∆ 4 P(s) + 5 O 2 (g) 2 P 2 O 5 (s) ∆ 2 Cl 2 (g) + O 2 (g) 2 Cl 2 O(g)

30. Nonmetal and Oxygen Gas 30 See video: http://www.youtube.com/watch?v=V1sQO91UvFI ∆ S(s) + O 2 (g) SO 2 (s)

31. Combination Reactions Metal and nonmetal metal + nonmetal  ionic compound 2 Na(s) + Cl 2 (g) 2 NaCl(s) Write a balanced chemical equation for each of the following: Chromium metal is heated with iodine crystals to give solid chromium(III) iodide Manganese metal reacts with bromine vapor to yield solid manganese(IV) bromide 31 © 2014 Pearson Education, Inc. ∆

32. Combination Reactions Metal and nonmetal metal + nonmetal  ionic compound 2 Na(s) + Cl 2 (g) 2 NaCl(s) Write a balanced chemical equation for each of the following: Chromium metal is heated with iodine crystals to give solid chromium(III) iodide Manganese metal reacts with bromine vapor to yield solid manganese(IV) bromide 32 © 2014 Pearson Education, Inc. ∆ ∆ 2 Cr(s) + 3 I 2 (s) 2 CrI 3 (s) ∆ Mn(s) + 2 Br 2 (g) MnBr 4 (s)

33. Metal and Nonmetal 33 See video: http://www.youtube.com/watch?v=Ftw7a5ccubs ∆ 2 Na(s) + Cl 2 (g) 2 NaCl(s)

34. Decomposition Reactions Metal hydrogen carbonates metal hydrogen carbonate metal carbonate + water + carbon dioxide 2 NaHCO 3 (s) Na 2 CO 3 (s) + H 2 O(g) + CO 2 (g) Write a balanced chemical equation for each of the following: Lead(II) hydrogen carbonate decomposes on heating Copper(I) hydrogen carbonate is decomposed with heat 34 © 2014 Pearson Education, Inc. ∆ ∆

35. Decomposition Reactions Metal hydrogen carbonates metal hydrogen carbonate metal carbonate + water + carbon dioxide 2 NaHCO 3 (s) Na 2 CO 3 (s) + H 2 O(g) + CO 2 (g) Write a balanced chemical equation for each of the following: Lead(II) hydrogen carbonate decomposes on heating Copper(I) hydrogen carbonate is decomposed with heat 35 © 2014 Pearson Education, Inc. ∆ ∆ ∆ Pb(HCO 3 ) 2 (s) PbCO 3 (s) + H 2 O(g) + CO 2 (g) ∆ 2 CuHCO 3 (s) Cu 2 CO 3 (s) + H 2 O(g) + CO 2 (g)

36. Metal Hydrogen Carbonates 36 See video: http://www.youtube.com/watch?v=mMVr7XC9_5Y ∆ 2 NaHCO 3 (s) Na 2 CO 3 (s) + H 2 O(g) + CO 2 (g)

37. Decomposition Reactions Metal carbonates metal carbonate metal oxide + carbon dioxide CuCO 3 (s) CuO(s) + CO 2 (g) Write a balanced chemical equation for each of the following: Copper(I) carbonate decomposes on heating Aluminum carbonate is decomposed on heating 37 © 2014 Pearson Education, Inc. ∆ ∆

38. Decomposition Reactions Metal carbonates metal carbonate metal oxide + carbon dioxide CuCO 3 (s) CuO(s) + CO 2 (g) Write a balanced chemical equation for each of the following: Copper(I) carbonate decomposes on heating Aluminum carbonate is decomposed on heating 38 © 2014 Pearson Education, Inc. ∆ ∆ ∆ Cu 2 CO 3 (s) Cu 2 O(s) + CO 2 (g) ∆ Al 2 (CO 3 ) 3 (s) Al 2 O 3 (s) + 3 CO 2 (g)

39. Metal Carbonates 39 See video: http://www.youtube.com/watch?v=TxbEgcjmhqo ∆ CuCO 3 (s) CuO(s) + CO 2 (g)

40. Decomposition Reactions Miscellaneous oxygen-containing compounds oxygen-containing compound substance + oxygen gas 2 HgO(s) 2 Hg( l ) + O 2 (g) Write a balanced chemical equation for each of the following: Solid potassium chlorate decomposes upon heating to give solid potassium chloride and oxygen gas Aqueous H 2 O 2 decomposes upon heating to give water and oxygen gas 40 © 2014 Pearson Education, Inc. ∆ ∆

41. Decomposition Reactions Miscellaneous oxygen-containing compounds oxygen-containing compound substance + oxygen gas 2 HgO(s) 2 Hg( l ) + O 2 (g) Write a balanced chemical equation for each of the following: Solid potassium chlorate decomposes upon heating to give solid potassium chloride and oxygen gas Aqueous H 2 O 2 decomposes upon heating to give water and oxygen gas 41 © 2014 Pearson Education, Inc. ∆ ∆ ∆ 2 KClO 3 (s) 2 KCl(s) + 3 O 2 (g) ∆ 2 H 2 O 2 (aq) 2 H 2 O( l ) + O 2 (g)

42. Miscellaneous Oxygen-Containing Compounds 42 See video: http://www.youtube.com/watch?v=_Y1alDuXm6A ∆ 2 HgO(s) 2 Hg( l ) + O 2 (g)

43. The Activity Series Concept The activity of a metal is its ability to compete in a single replacement reaction – order of this is known as an activity series Li > K > Ba > Sr > Ca > Na > Mg > Al > Mn > Zn > Fe > Cd > Co > Ni > Sn > Pb > (H) > Cu > Ag > Hg > Au Hydrogen (H) is included in the series to show which metals react with acids – Cu, Ag, Hg, Au do not (no reaction, NR); others do Examples: Fe(s) + CuSO 4 (aq)  FeSO 4 (aq) + Cu(s) Cu(s) + FeSO 4 (aq)  NR Cu(s) + H 2 SO 4 (aq)  NR 43 © 2014 Pearson Education, Inc.

44. The Activity Series Concept Some metals are so reactive, they react directly with water at room temperature – known as active metals (Li, Na, K, Rb, Cs, Ca, Sr, Ba) There is also an activity series for halogens (F > Cl > Br > I) Cl 2 (g) + 2 NaBr(aq)  2 NaCl(aq) + Br 2 ( l ) Predict whether or not a reaction occurs for the following: A gold ring is dropped into sulfuric acid A zinc granule is dropped into hydrochloric acid A cadmium foil is put into a lead(II) nitrate solution A chromium strip is put into water Aluminum foil is added to an iron(II) sulfate solution 44 © 2014 Pearson Education, Inc.

45. The Activity Series Concept Some metals are so reactive, they react directly with water at room temperature – known as active metals (Li, Na, K, Rb, Cs, Ca, Sr, Ba) There is also an activity series for halogens (F > Cl > Br > I) Cl 2 (g) + 2 NaBr(aq)  2 NaCl(aq) + Br 2 ( l ) Predict whether or not a reaction occurs for the following: A gold ring is dropped into sulfuric acid No Reaction (NR) A zinc granule is dropped into hydrochloric acid Reaction Occurs A cadmium foil is put into a lead(II) nitrate solution Reaction Occurs A chromium strip is put into water No Reaction (NR) Aluminum foil is added to an iron(II) sulfate solution Reaction Occurs 45 © 2014 Pearson Education, Inc.

46. Single-Replacement Reactions Metal and aqueous salt solution metal 1 (s) + salt 1 (aq)  metal 2 (s) + salt 2 (aq) Cu(s) + 2 AgNO 3 (aq) 2 Ag(s) + Cu(NO 3 ) 2 (aq) Write a balanced chemical equation for each of the following: Nickel metal is placed in a tin(II) sulfate solution Gold metal is placed in a silver nitrate solution 46 © 2014 Pearson Education, Inc.

47. Single-Replacement Reactions Metal and aqueous salt solution metal 1 (s) + salt 1 (aq)  metal 2 (s) + salt 2 (aq) Cu(s) + 2 AgNO 3 (aq) 2 Ag(s) + Cu(NO 3 ) 2 (aq) Write a balanced chemical equation for each of the following: Nickel metal is placed in a tin(II) sulfate solution Gold metal is placed in a silver nitrate solution 47 © 2014 Pearson Education, Inc. Ni(s) + SnSO 4 (aq) NiSO 4 (aq) + Sn(s) Au(s) + AgNO 3 (aq) NR

48. Cu(s) + 2 AgNO 3 (aq) 2 Ag(s) + Cu(NO 3 ) 2 (aq) Metal and Aqueous Salt Solution 48 See video: http://www.youtube.com/watch?v=P5QlfMRvvF8

49. Single-Replacement Reactions Metal and aqueous acid solution metal(s) + acid(aq)  salt(aq) + hydrogen(g) Zn(s) + H 2 SO 4 (aq) ZnSO 4 (aq) + H 2 (g) Write a balanced chemical equation for each of the following: A chunk of cadmium metal is dropped into hydrochloric acid Manganese chips are added to sulfuric acid 49 © 2014 Pearson Education, Inc.

50. Single-Replacement Reactions Metal and aqueous acid solution metal(s) + acid(aq)  salt(aq) + hydrogen(g) Zn(s) + H 2 SO 4 (aq) ZnSO 4 (aq) + H 2 (g) Write a balanced chemical equation for each of the following: A chunk of cadmium metal is dropped into hydrochloric acid Manganese chips are added to sulfuric acid 50 © 2014 Pearson Education, Inc. Cd(s) + 2 HCl(aq) CdCl 2 (aq) + H 2 (g) Mn(s) + H 2 SO 4 (aq) MnSO 4 (aq) + H 2 (g)

51. Metal and Aqueous Acid Solution 51 See video: http://www.youtube.com/watch?v=9hBCLoWwcWo Zn(s) + H 2 SO 4 (aq) ZnSO 4 (aq) + H 2 (g)

52. Single-Replacement Reactions Active metal and water metal(s) + water( l )  metal hydroxide(aq) + hydrogen(g) Ca(s) + 2 H 2 O( l ) Ca(OH) 2 (aq) + H 2 (g) Write a balanced chemical equation for each of the following: A chunk of iron metal is dropped into water A small piece of strontium metal is dropped into water 52 © 2014 Pearson Education, Inc.

53. Single-Replacement Reactions Active metal and water metal(s) + water( l )  metal hydroxide(aq) + hydrogen(g) Ca(s) + 2 H 2 O( l ) Ca(OH) 2 (aq) + H 2 (g) Write a balanced chemical equation for each of the following: A chunk of iron metal is dropped into water A small piece of strontium metal is dropped into water 53 © 2014 Pearson Education, Inc. Fe(s) + H 2 O( l ) NR Sr(s) + 2 H 2 O( l ) Sr(OH) 2 (aq) + H 2 (g)

54. Active Metal and Water 54 See video: http://www.youtube.com/watch?v=Y9CpQAjqHHo Ca(s) + 2 H 2 O( l ) Ca(OH) 2 (aq) + H 2 (g)

55. Solubility Rules In double-replacement reactions, two aqueous solutions may react to form a compound that is not soluble (a precipitate) There are rules to determine if a compound will be soluble or not: 55 © 2014 Pearson Education, Inc.

56. Applying Solubility Rules Are the following compounds soluble or insoluble in water?: sodium sulfate aluminum nitrate barium sulfate lead(II) chromate ammonium sulfide lead(II) acetate mercury(II) bromide magnesium carbonate zinc phosphate calcium hydroxide 56 © 2014 Pearson Education, Inc.

57. Applying Solubility Rules Are the following compounds soluble or insoluble in water?: sodium sulfate Na 2 SO 4 soluble aluminum nitrate Al(NO 3 ) 3 soluble barium sulfate BaSO 4 insoluble lead(II) chromate PbCrO 4 insoluble ammonium sulfide (NH 4 ) 2 S soluble lead(II) acetate Pb(C 2 H 3 O 2 ) 2 soluble mercury(II) bromide HgBr 2 soluble magnesium carbonate MgCO 3 insoluble zinc phosphate Zn 3 (PO 4 ) 2 insoluble calcium hydroxide Ca(OH) 2 soluble 57 © 2014 Pearson Education, Inc.

58. Double-Replacement Reactions Double-replacement reactions salt 1 (aq) + salt 2 (aq)  salt 3 (s) + salt 4 (aq) Pb(NO 3 ) 2 (aq) + 2 KI(aq) PbI 2 (s) + KNO 3 (aq) Write a balanced chemical equation for each of the following: Aqueous cobalt(II) nitrate is added to a sodium chromate solution Aqueous strontium acetate is added to a lithium hydroxide solution 58 © 2014 Pearson Education, Inc.

59. Double-Replacement Reactions Double-replacement reactions salt 1 (aq) + salt 2 (aq)  salt 3 (s) + salt 4 (aq) Pb(NO 3 ) 2 (aq) + 2 KI(aq) PbI 2 (s) + KNO 3 (aq) Write a balanced chemical equation for each of the following: Aqueous cobalt(II) nitrate is added to a sodium chromate solution Aqueous strontium acetate is added to a lithium hydroxide solution 59 © 2014 Pearson Education, Inc. Co(NO 3 ) 2 (aq) + Na 2 CrO 4 (aq) CoCrO 4 (s) + 2 NaNO 3 (aq) Sr(C 2 H 3 O 2 ) 2 (aq) + LiOH(aq) NR

60. Double-Replacement Reactions 60 See video: http://www.youtube.com/watch?v=TRq9hnOGvaE Pb(NO 3 ) 2 (aq) + 2 KI(aq) PbI 2 (s) + KNO 3 (aq)

61. Neutralization Reactions Neutralization reactions acid(aq) + base(aq)  salt(aq) + water( l ) HCl(aq) + NaOH(aq) NaCl(aq) + HOH( l ) * An acid-base indicator is often added to show evidence of the reaction Write a balanced chemical equation for each of the following: Nitric acid and ammonium hydroxide produce ammonium nitrate and water Chloric acid neutralizes a strontium hydroxide solution 61 © 2014 Pearson Education, Inc.

62. Neutralization Reactions Neutralization reactions acid(aq) + base(aq)  salt(aq) + water( l ) HCl(aq) + NaOH(aq) NaCl(aq) + HOH( l ) * An acid-base indicator is often added to show evidence of the reaction Write a balanced chemical equation for each of the following: Nitric acid and ammonium hydroxide produce ammonium nitrate and water Chloric acid neutralizes a strontium hydroxide solution 62 © 2014 Pearson Education, Inc. HNO 3 (aq) + NH 4 OH(aq) NH 4 NO 3 (aq) + HOH( l ) 2 HClO 3 (aq) + Sr(OH) 2 (aq) Sr(ClO 3 ) 2 (aq) + 2 HOH( l )

63. Neutralization Reactions 63 See video: http://www.youtube.com/watch?v=AIiQce07u2o HCl(aq) + NaOH(aq) NaCl(aq) + HOH( l )

64. Household Chemicals 64 © 2014 Pearson Education, Inc. phosphoric acid carbonic acid acetic acid citric acid acetylsalicylic acid ammonia sodium hydroxide (ammonium chlorides) magnesium sulfate hydrate

65. Summary 65 © 2014 Pearson Education, Inc. Evidence for a chemical reaction is any of the following: a gas is detected, a precipitate is formed in an aqueous solution, a color change is observed, or a change in energy is observed (exothermic reaction releases heat and endothermic reaction absorbs heat) A reactant undergoes a chemical change to become a product, a catalyst speeds up a reaction without being permanently altered, a chemical equation describes a reaction using formulas and symbols, and it is important to remember that the following elements occur naturally as diatomic molecules (H 2, N 2, O 2, F 2, Cl 2, Br 2, I 2 ) Coefficients are added to a chemical equation to properly balance it (same number of atoms of each element per side), the subscript in a chemical formula should not be changed during balancing

66. Summary 66 © 2014 Pearson Education, Inc. Most chemical reactions are classified as: combination, decomposition, single-replacement, double-replacement, or neutralization Three types of combination reactions: metal and oxygen, nonmetal and oxygen, metal and nonmetal Three types of decomposition reactions: metal hydrogen carbonate, metal carbonate, miscellaneous oxygen-containing compounds The activity series lists the relative ability of a metal to undergo a reaction (a metal higher in the series replaces a lower metal), active metals (including Li, Na, K, Ba, Sr and Ca) produce H 2 gas in water Three types of single-replacement reactions: metal and aqueous solution, metal and dilute acid, active metal and water

67. Summary 67 © 2014 Pearson Education, Inc. To predict whether a substance is soluble or not, refer to the solubility rules (Table 7.2 in your book) In a double-replacement reaction, a precipitation occurs In a neutralization reaction, an acid and a base react to yield salt and water (special type of double-replacement reaction) Key terms: chemical reaction, precipitate, aqueous solution, exothermic reaction, endothermic reaction, reactant, product, catalyst, chemical equation, diatomic molecule, coefficient, subscript, combination reaction, decomposition reaction, single- replacement reaction, double-replacement reaction, neutralization reaction, activity series, active metal, acid, base, salt