Types of Chemical Reactions

1. Types of Chemical Reactions 5 basic types of chemical reactions: • Synthesis reactions • Decomposition reactions • Single Replacement reactions • Double Replacement reactions • Combustion reactions

2. Types of Reactions • You need to be able to identify the type of reaction and balance reaction • Honors Students need to also predict product(s)

3. Steps to Writing Reactions • Identify the type of reaction • Predict product(s) • Make sure formula of products are correctly written! • Balance it Don’t forget about the diatomic elements! (BrINClHOF) Ex: Oxygen is O2 as anelement. In a compound, it can’t be a diatomic element because it’s not an element anymore, it’s a compound!

4. Synthesis Reactions • Two substances (generallyelements) combine and form a compound. • Also called combination or addition reactions reactant + reactant  1 product A + B  AB • Ex: 2H2 + O2  2H2O • Ex: C+ O2  CO2

5. Synthesis Reactions • Another example of a synthesis reaction

6. Predict the products and balance the following synthesis reaction equations. • Check charges and criss-cross to see what formulas would be when elements pair up • Sodium metal reacts with chlorine gas Na(s) + Cl2(g) _________ • Solid Magnesium reacts with fluorine gas Mg(s) + F2(g)  __________ • Aluminum metal reacts with fluorine gas Al(s) + F2(g)  __________

7. Decomposition Reactions A compound breaks up into elements or into a few simpler compounds 1 Reactant  Product + Product AB  A + B • Ex: 2 H2O  2H2 + O2 • Ex: 2 HgO  2Hg + O2

8. Decomposition Reactions

9. Decomposition Exceptions (Honors) • Carbonates and chlorates are special case decomposition reactions that do not break down to elements • Carbonates (CO32-) decompose to carbon dioxide and a metal oxide • Example: CaCO3  CO2 + CaO • Chlorates (ClO3-) decompose to oxygen gas and a metal chloride • Example: 2 Al(ClO3)3  2 AlCl3 + 9 O2

10. Practice • Predict the products • Write formulas of products correctly • (Remember diatomic elements!!) • Balance the following decomposition reactions • PbO2(s)  _____________________ • AlN(s) ________________________

11. Single Replacement Reactions • One element replaces another in a compound. • A metal can replace a metal (+) OR a nonmetal can replace a nonmetal (-) element + compound element + compound 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!)

12. Using Table J • An element can only replace an element that is “less active” than itself in a compound. • Use Table J to predict is a Single Replacement reaction can occur. Li + MgCl2 → Ag + MgCl2 → F2 + NaCl → Br2 + NaCl →

13. Single Replacement Reactions Write and balance the following single replacement reaction equation: • Zinc metal reacts with aqueous hydrochloric acid Zn(s) + HCl(aq) Note: Zinc replaces the hydrogen ion in the reaction

14. Single Replacement Reactions • Sodium chloride solid reacts with fluorine gas NaCl(s) + F2(g)  ______________ • Aluminum metal reacts with copper (II) nitrate(aq) Al(s)+ Cu(NO3)2(aq)_______________

15. Double Replacement Reactions A metal replaces a metal in a compound and a nonmetal replaces a nonmetal in a compound • Ions “switch partners” • Forms and insoluble precipitate and/or water Compound + compound  compound+ compound AB + CD  AD + CB

16. Double Replacement Reactions • First & last ions go together, inside ions go together. • All ions keep their original charges with new partners • Ex: AgNO3(aq) + NaCl(s)  AgCl(s) + NaNO3(aq) • Ex: K2SO4(aq) + Ba(NO3)2(aq)  2KNO3(aq) + BaSO4(s)

17. Practice Predict the products. Balance the equation • HCl(aq) + AgNO3(aq)  • CaCl2(aq) + Na3PO4(aq)  • Pb(NO3)2(aq) + BaCl2(aq)  • FeCl3(aq) + NaOH(aq)  • H2SO4(aq) + NaOH(aq) 

18. Combustion Reactions • A hydrocarbon reacts with oxygen gas. • This is also called burning!!! • In order to burn something you need the 3 things in the “fire triangle”: • Fuel (hydrocarbon) • Oxygen to burn it with • Something to ignite the reaction (spark)

19. Combustion Reactions • In general: CxHy+ O2  CO2 + H2O • Products in combustion are ALWAYS carbon dioxide and water. • Although incomplete burning does cause some by-products like carbon monoxide (CO) and soot (solid carbon) • Combustion is used to heat homes and run automobiles • Ex: Octane, as in gasoline, is C8H18

20. Combustion • C5H12 + O2 CO2 + H2O • Write products and balance the following combustion reaction: C10H22 + O2 

21. Mixed Practice State the type, predict the products, and balance the following reactions: TYPE • _________ BaCl2 + H2SO4 • _________ C6H12 + O2  • _________ Zn + CuSO4  • _________ Cs + Br2  • _________ FeCl3 

22. Writing Ionic Equations (Honors) Balanced Equation: K2CrO4(aq) + Pb(NO3)2(aq) PbCrO4 (s) + 2 KNO3 (aq) Soluble Soluble Insoluble Soluble Ionic Equation: Shows all dissolved ions (aq) separated and precipitate together 2 K+ + CrO4-2 + Pb+2 + 2 NO3-  PbCrO4 (s) + 2 K+ + 2 NO3-

23. Net Ionic Equations (Honors) • Same as ionic equations, but cancel out ions that appear on BOTH sides of the equation • these are the SPECTATOR IONS Ionic Equation: 2K+ + CrO4-2 + Pb+2 + 2NO3- PbCrO4(s) + 2K+ +2NO3- Net Ionic Equation: Shows formation of Precipitate CrO4-2 + Pb+2  PbCrO4 (s)

24. Net Ionic Equations (HONORS) • Write the balanced equation, ionic, and net ionic equations for this reaction: • Silver nitrate reacts with Lead (II) Chloride in water. Balanced Equation: Total Ionic: Net Ionic: