2. Types of Chemical Reactions

3. Types of Reactions There are six types of chemical reactions we will talk about: 1. 1. Synthesis reactions (syn) 2. 2. Decomposition reactions (decomp) 3. 3. Single replacement reactions (SR) 4. 4. Double replacement reactions (DR) 5. 5. Combustion reactions (Comb) 6. 6. Oxidation-Reduction reactions (Redox)

4. Synthesis Reactions Synthesis Reactions (AKA Combination or Addition) Two substances (generally elements) combine and form a compound. reactant + reactant  1 product A + B  AB 2H 2 + O 2  2H 2 O C + O 2  CO 2

5. Synthesis Reactions

6. Decomposition Reactions Compound breaks up into the elements or into a few simpler compounds 1 Reactant  Product + Product AB  A + B 2 H 2 O  2H 2 + O 2 2 HgO  2Hg + O 2

7. Decomposition Reactions

8. Single Replacement or Displacement Reactions One element replaces another in a compound metal can replace a metal (+) OR nonmetal can replace a nonmetal (-) element + compound  product + product A + BC  AC + B (if A is a metal) OR A + BC  BA + C (if A is a nonmetal) (remember the cation always goes first!)

10. Single Replacement Reactions

11. Sodium chloride solid reacts with fluorine gas NaCl (s) + F 2(g)  NaF (s) + Cl 2(g) Note that fluorine replaces chlorine in the compound Aluminum metal reacts with aqueous copper (II) nitrate Al (s) + Cu(NO 3 ) 2(aq)  Cu (s) + Al(NO 3 ) 3(aq) 22 23 3 2

12. Double Replacement Reactions Two compounds switch components metal replaces a metal and nonmetal replaces a nonmetal Compound + compound  product + product AB + CD  AD + CB

14. Double Replacement Reactions Think about it like “foil”ing in algebra, first and last ions go together + inside ions go together Examples: AgNO 3(aq) + NaCl (s)  AgCl (s) + NaNO 3(aq) K 2 SO 4(aq) + Ba(NO 3 ) 2(aq)  KNO 3(aq) + BaSO 4(s) 2

15. Combustion Reactions Combustion Reactions Hydrocarbon reacts with oxygen gas to form carbon dioxide and water and energy C y H x + O 2 → CO 2 + H 2 O + E (heat) Methane- Natural Gas CH 4

17. Combustion Reactions A car has an internal combustion engine A car has an internal combustion engine

18. Gasoline

19. By Products of Fuel Combustion NO x SO x CO

20. Incomplete Combustion Reactions Edgar Allen Poe’s drooping eyes and mouth are potential signs of CO poisoning.

21. Combustion Example C 5 H 12 + O 2  CO 2 + H 2 O Write the products and balance the following combustion reaction: C 10 H 22 + O 2  5 6 8 CO 2 + H 2 O10 11 2 312022

22. Oxidation-Reduction (Redox) Many of the 5 types of reactions are also oxidation-reduction reactions Oxidation: Loss of electrons (RA) Reduction: Gain of electrons (OA)

23. You can’t have one… without the other! If an element (metal) is losing e-, then another element (nonmetal) has to gain e- There has to be conservation of e- lost and gained in a reaction LEO the lion says GER! o s e l e c t r o n s x i d a t i o n a i n l e c t r o n s e d u c t i o n GER!

24. Another Pneumonic OIL RIG OIL RIG x i d a t i o n s o s e e d u c t i o n s a i n

25. Mixed Practice State the type and balance the following reactions: 1. 1. BaCl 2 + H 2 SO 4  2. 2. C 6 H 12 + O 2  3. 3. Zn + CuSO 4  4. 4. Cs + Br 2  5. 5. FeCO 3  BaSO 4 + HCl2 CO 2 + H 2 O 66 9 ZnSO 4 + Cu CsBr22 FeO + CO 2