2. TYPES OF CHEMICAL REACTIONS

3. Today’s lesson Title: Types of chemical reactions Focus: To classify a chemical reaction as one of the following types: combination (synthesis), decomposition, single replacement, double replacement, neutralization or combustion. Success Criteria: I have recorded information on each type of chemical reaction in my workbook. I can successfully classify all six different types of chemical reactions.

4. Types of Chemical Reactions SynthesisSynthesis (Combination) reaction DecompositionDecomposition reaction Single-replacementSingle-replacement reaction Double-replacement reaction Neutralization reaction Combustion reaction 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 elementcompoundelementcompound acidbasesaltwater

5. Chemical Equations

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. SYNTHESIS REACTION SUMMARY A synthesis reaction is when two or more simple compounds combine to form a more complicated one.

9. Precipitation Reactions Precipitation reactions result in an insoluble solid being formed when two clear solutions are mixed together. soluble salt A + soluble salt B  insoluble salt C + soluble salt D

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

11. 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) + +

12. 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) + +

13. 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

14. Decomposition Reaction A decomposition reaction is the opposite of a synthesis reaction – a complex molecule breaks down to make a simple one.

15. Single Replacement Reaction Single-replacement reaction Mg + CuSO 4  MgSO 4 + Cu General form: A + BC  AC + B Single replacement reaction is when one element trades places with another element in a compound.

16. Double Replacement Reaction Double-replacement reaction CaCO 3 + 2 HCl  CaCl 2 + H 2 CO 3 General form: AB + CD  AD + CB This is a reaction in which the positive and negative ions of two substances in a solution are mutually interchanged.

17. 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

18. Neutralisation Reaction Otherwise known as an acid-base reaction The H+ ion in the acid reacts with the OH- ion in the base, causing the formation of water. Acid + Base  Salt + Water

19. Potassium reacts with Water P O W !

20. 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 ++

21. 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

22. 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

23. 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.

24. 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

25. Combustion Reaction A combustion reaction is when oxygen combines with another compound to form water and carbon dioxide. An example: CH 4 (g) + 2O 2 (g) → CO 2 (g) + 2H 2 O(l) Hydrocarbon: A hydrocarbon is a compound that contains the elements hydrogen and carbon.

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