2. Chemical Equations & Reactions Chapter 8 Lesson 2 http://www.unit5.org/chemistry/Equations.html

3. Types of Chemical Reactions SynthesisSynthesis (Combination) reaction DecompositionDecomposition reaction A Single-replacement reaction Single-replacement B Double-replacement reaction Neutralization reaction Combustion reaction (of a hydrocarbon) A + B  AB AB  A + B A + BC  AC + B AB + CD  AD + CB HX + BOH  BX + HOH CH + O 2  CO 2 + H 2 O A use activity series to predictactivity series B driving force…water, gas, or precipitate Polymerization Polymer = monomer + monomer + … elementcompoundelementcompound acidbasesaltwater

4. Types of Chemical Reactions Synthesis (Combination) reaction Decomposition reaction A Single-replacement reaction B Double-replacement reaction Neutralization reaction Combustion reaction (of a hydrocarbon) A + B  AB AB  A + B A + BC  AC + B AB + CD  AD + CB HX + BOH  BX + HOH CH + O 2  CO 2 + H 2 O A use activity series to predictactivity series B driving force…water, gas, or precipitate Polymerization Polymer = monomer + monomer + …

5. Chemical Equations 1 molecule N 2 3 molecules H 2 2 molecules NH 3 + + + + + 1 mol N 2 3 mol H 2 2 mol NH 3 1 mol N 2 3 mol H 2 2 mol NH 3 N2 (g)N2 (g) 3 H 2 (g) 2 NH 3 (g) “Microscopic recipe” “Macroscopic recipe” Experimental Conditions Reactants Products Chemical Equations 2 molecules N 2 3 molecules H 2 0 molecules NH 3 1 molecules N 2 0 molecules H 2 2 molecules NH 3 Before reaction After reaction Nitrogen is in excess – or hydrogen is limiting reagent.

6. Synthesis Reaction Direct combination reaction (Synthesis) General form: A + B  AB element orelement or compoundcompound Na Cl Na Cl 2 Na + Cl 2  2 NaCl  Cl Na Cl

7. Synthesis Reaction Direct combination reaction (Synthesis) General form: A + B  AB element orelement or compoundcompound Na + Cl - Na ClNa Cl Na + Cl - 2 Na + Cl 2  2 NaCl

8. Formation of a solid: AgCl AgNO 3 (aq) + KCl(aq)  KNO 3 (aq) + AgCl(s)

9. Copyright © 2007 Pearson Benjamin Cummings. All rights reserved. PbI 2 K 1+ Pb 2+ lead (II) chloride + potassium iodide Cl 2 I Pb 2+ Pb K 1+ K Cl 1- I 1- Cl 1- I 1- KCl potassium chloride lead (II) iodide + (aq) (ppt) + +

10. Copyright © 2007 Pearson Benjamin Cummings. All rights reserved. PbI 2 K 1+ Pb 2+ lead (II) chloride + potassium iodide Cl 2 I Pb 2+ Pb K 1+ K Cl 1- I 1- Cl 1- I 1- KCl potassium chloride lead (II) iodide + (aq) (ppt) + +

11. H H H H Decomposition Reaction H H H H O Decomposition reaction 2 H 2 O 2 H 2 O2O2 General form: ABAB + + + compoundtwo or more elements or compounds OO O

12. Single and Double Replacement Reactions Double-replacement reaction CaCO 3 + 2 HCl  CaCl 2 + H 2 CO 3 General form: AB + CD  AD + CB Single-replacement reaction Mg + CuSO 4  MgSO 4 + Cu General form: A + BC  AC + B

13. Ca Activity Series Foiled again – Aluminum loses to Calcium Element Reactivity Li Rb K Ba Ca Na Mg Al Mn Zn Cr Fe Ni Sn Pb H 2 Cu Hg Ag Pt Au Halogen Reactivity F 2 Cl 2 Br 2 I 2 Printable Version of Activity Series Printable Version of Activity Series

15. TABLE OF SOLUBILITIES IN WATER aluminum sssnsnissisd ammonium sssssssssss barium ssisisssiid calcium ssissssssi d copper (II) ssisiinsisi iron (II) ssisnissisi iron (III) ssnsiinsissd lead sssi ii siii magnesium ssississisd mercury (I) ssiii nisi i mercury (II) sssis iisidi potassium sssssssssss silver ssiii nisi i sodium sssssssssss zinc ssississisi acetate bromide carbonate chloride chromate hydroxide iodide nitrate phosphate sulfate sulfide

16. TABLE OF SOLUBILITIES IN WATER aluminum sssnsnissisd ammonium sssssssssss barium ssisisssiid calcium ssissssssi d copper (II) ssisiinsisi iron (II) ssisnissisi iron (III) ssnsiinsissd lead sssi ii siii magnesium ssississisd mercury (I) ssiii nisi i mercury (II) sssis iisidi potassium sssssssssss silver ssiii nisi i sodium sssssssssss zinc ssississisi acetate bromide carbonate chloride chromate hydroxide iodide nitrate phosphate sulfate sulfide i = insoluble ss = slightly soluble s = soluble d = decomposes n = not isolated SOLID AQUEOUS Legend

17. TABLE OF SOLUBILITIES IN WATER aluminum saqnsns s d ammonium aq barium aq s s ssd calcium aq s ssaq ssd copper (II) aq s ssn s s iron (II) aq s nss s s iron (III) aq n ssn ssd lead aqsssssssaqsss magnesium aq s s s d mercury (I) sssssnsaqsssi mercury (II) aqss sss sdsi potassium aq silver sssssnsssss sodium aq zinc aq s s s s acetate bromide carbonate chloride chromate hydroxide iodide nitrate phosphate sulfate sulfide Legend s = solid aq = aqueous d = decomposes n = not isolated

18. TABLE OF SOLUBILITIES IN WATER aluminum saqnsns s d ammonium aq barium aq s s ssd calcium aq s ssaq ssd copper (II) aq s ssn s s iron (II) aq s nss s s iron (III) aq n ssn ssd lead aqsssssssaqsss magnesium aq s s s d mercury (I) sssssnsaqsssi mercury (II) aqss sss sdsi potassium aq silver sssssnsssss sodium aq zinc aq s s s s acetate bromide carbonate chloride chromate hydroxide iodide nitrate phosphate sulfate sulfide Legend s = solid aq = aqueous d = decomposes n = not isolated

19. TABLE OF SOLUBILITIES IN WATER aluminum sssnsnissisd ammonium sssssssssss barium ssisisssiid calcium ssissssssi d copper (II) ssisiinsisi iron (II) ssisnissisi iron (III) ssnsiinsissd lead sssi ii siii magnesium ssississisd mercury (I) ssiii nisi i mercury (II) sssis iisidi potassium sssssssssss silver ssiii nisi i sodium sssssssssss zinc ssississisi acetate bromide carbonate chloride chromate hydroxide iodide nitrate phosphate sulfate sulfide Legend s = solid aq = aqueous d = decomposes n = not isolated

20. Potassium reacts with Water P O W !

21. Double Replacement Reaction K 2 CO 3 (aq) Potassium carbonate BaCl 2 (aq) Barium chloride 2 KCl (aq) Potassium chloride BaCO 3 (s) Barium carbonate ++

22. Synthesis Reactions CO 2 + H 2 O C 6 H 12 O 6 + O 2 H 2 + O 2 H 2 O Na + Cl 2 NaCl 66 6 Photosynthesis Formation of water 22 22 Formation of salt A + B C General Form

23. H 2 O H 2 + O 2 electricity Decomposition Reactions H 2 O 2 H 2 O + O 2 NI 3 N 2 + I 2 2 2 Hydrogen Peroxide Electrolysis of water 22 Nitrogen triiodide AB A + B General Form 2 3

24. Mg + AlCl 3 Al + MgCl 2 Predict if these reactions will occur Al + MgCl 2 Can magnesium replace aluminum? Activity Series YES, magnesium is more reactive than aluminum. 2233 Can aluminum replace magnesium? Activity Series NO, aluminum is less reactive than magnesium. Therefore, no reaction will occur. No reaction MgCl 2 + Al No reaction The question we must ask is can the single element replace its counterpart? metal replaces metal or nonmetal replaces nonmetal. Order of reactants DOES NOT determine how they react.

25. Single-Replacement Reactions FeCl 2 + Cu MgBr 2 + Cl 2 “Magic blue-earth” Zinc in nitric acid 2 A + BC AC + B General Form Zn(NO 3 ) 2 + H 2 Can Fe replace Cu? Yes Li Rb K Ba Ca Na Mg Al Mn Zn Cr Fe Ni Sn Pb H 2 Cu Hg Ag Pt Au F 2 Cl 2 Br 2 I 2 Can Zn replace H? Yes Can Br replace Cl? No NO REACTION Fe + CuCl 2 Zn + HNO 3 MgCl 2 + Br 2 Activity Series

26. Write a balanced chemical equation for the following combustion reactions: A. C 5 H 12 B. C 22 H 46 C. C 15 H 28 + O 2  CO 2 + H 2 O 8 5 6 67 44 462 + O 2  CO 2 + H 2 O 22 15 14

27. H2OH2O KOH + HNO 3 KNO 3 + H 2 O H K NO 3 OH H K How would you prepare potassium nitrate (using a double replacement reaction)? KNO 3 _________ + + Ca(NO 3 ) 2 Both potassium nitrate and calcium chloride are soluble (no driving force – no reaction!) H2OH2O formation of water is a driving force. potassium nitrate Combine a potassium hydroxide solution with nitric acid to yield soluble potassium nitrate. The water could then be removed by distillation to recover solid potassium nitrate. _________ Ca(NO 3 ) 2 KNO 3 Ca(OH) 2 KOH + + 22 KOH(aq) + HNO 3 (aq) KNO 3 (aq) + ?