1. Unit 7 Chemical Reactions
Types of Reactions

2. Type of Reactions
Chemical reactions are classified into five general types
Synthesis (also called combination or addition)
Decomposition
Single Replacement (also called single displacement)
Double Replacement(also called double displacement)
Combustion

3. Synthesis (Combination)
Two or more elements or simple compounds combine to form (synthesize) one product
A + B AB
2Mg + O2 2MgO
2Na + Cl2 2NaCl
SO3 + H2O H2SO4
When two elements combine in synthesis, the product is a compound made of their respective ions.

4. Combination (Synthesis)
YouTube - Reaction of Sodium & Chlorine (with subtitles)

5. Synthesis (practice)
Predict the products. Write and balance the following synthesis reaction equations.
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) 

6. Combination (Synthesis) Practice
Predict the products. Write and balance the following synthesis reaction equations.
Sodium metal reacts with chlorine gas
2 Na(s) + Cl2(g)  2 NaCl
Solid Magnesium reacts with fluorine gas
Mg(s) + F2(g)  MgF2
Aluminum metal reacts with fluorine gas
2Al(s) + 3 F2(g)  2AlF3

7. Decomposition AB A + B 2HgO 2Hg + O2 2KClO3 2KCl + 3 O2
One substance is broken down (split) into two or more simpler substances.
AB A + B
2HgO 2Hg + O2
2KClO3 2KCl + 3 O2
a compound made of two elements, decomposes into those elements.

8. Decomposition
YouTube - ammonium dichromate volcano

9. Decomposition Practice
Predict the products. Then, write and balance the following decomposition reaction equations:
Solid Lead (IV) oxide decomposes PbO2(s) 
Aluminum nitride decomposes
AlN(s) 

10. Decomposition Practice
Predict the products. Then, write and balance the following decomposition reaction equations:
Solid Lead (IV) oxide decomposes PbO2 (s)  Pb (s) + O2 (g)
Aluminum nitride decomposes
2AlN(s) 2 Al (s) + N2 (g)

11. Learning Check 1
Classify the following reactions as 1) combination or 2) decomposition: ___A. H2 + Br2 2HBr ___B. Al2(CO3)3 Al2O3 + 3CO2 ___C. 4 Al + 3C Al4C3

12. Solution 1
Classify the following reactions as 1) combination or 2) decomposition: _1_A. H2 + Br2 2HBr _2_B. Al2(CO3)3 Al2O3 + 3CO2 _1_C. 4 Al + 3C Al4C3

13. Single Replacement (Displacement)
One element takes the place of an element in a reacting compound.
A + BC AC + B
Zn + 2HCl ZnCl H2
Fe + CuSO4 FeSO4 + Cu
A metal can replace a metal (+) OR a nonmetal can replace a nonmetal (-).
Whether one metal will displace another metal from a compound depends on the relative reactivity's of the two metals.

14. Single Replacement (Displacement) Practice
YouTube - Thermite reaction

15. Single Replacement Displacement)
Lithium
Potassium
Calcium
Sodium
Magnesium
Aluminum
Zinc
Iron
Lead
Hydrogen
Copper
Mercury
silver
The activity series of metals lists metals in order of decreasing reactivity.
A metal will replace any metal listed below.

16. Single Replacement (Displacement) Practice
Sodium chloride solid reacts with fluorine gas
NaCl(s) + F2(g) 
Aluminum metal reacts with aqueous copper (II) nitrate
Al(s)+ Cu(NO3)2(aq)

17. Single Replacement (Displacement) Practice
Sodium chloride solid reacts with fluorine gas
2NaCl(s) + F2(g)  2 NaF(s) + Cl2(g)
Note that fluorine (nonmetal) replaces chlorine (nonmetal) in the compound
Aluminum metal reacts with aqueous copper (II) nitrate
2 Al(s)+ 3Cu(NO3)2(aq) 3Cu(s) + 2 Al(NO3)3

18. Double Replacement (Displacement)
Two elements in reactants take the place of each other AB + CD AD + CB AgNO3 + NaCl AgCl + NaNO3 ZnS + 2HCl ZnCl2 + H2S

19. Double Replacement (Displacement)
YouTube - Double Replacement Reactions

20. Double Replacement Practice
Think about it like “foil”ing in algebra, first and last ions go together ; inside ions go together
Example:
AgNO3(aq) + NaCl(s)  AgCl(s) + NaNO3(aq)
Another example:
K2SO4(aq) + Ba(NO3)2(aq)  KNO3(aq) + BaSO4(s)

21. Double Replacement Practice
Classify the following reactions as 1) single replacement 2) double replacement __A. 2Al + 3H2SO4 Al2(SO4)3 + 3H2 __B. Na2SO4 + 2AgNO3 Ag2SO4 + 2NaNO3 __C. 3C + Fe2O3 2Fe + 3CO

22. Double Replacement Practice
Classify the following reactions as 1) single replacement 2) double replacement 1_A. 2Al + 3H2SO4 Al2(SO4)3 + 3H2 2_B. Na2SO4 + 2AgNO3 Ag2SO4 + 2NaNO3 1_C. 3C + Fe2O3 2Fe + 3CO

23. Double Replacement Practice
Predict the products. Balance the equation
HCl(aq) + AgNO3(aq) 
2. CaCl2(aq) + Na3PO4(aq) 

24. Double Replacement Practice
Predict the products. Balance the equation
HCl(aq) + AgNO3(aq)  HNO3 + AgCl
2. CaCl2(aq) + Na3PO4(aq) Ca3(PO4)2 + NaCl

25. Combustion
A reaction in which a hydrocarbon (compound made up of H and C) reacts with oxygen and the products are carbon dioxide and water CH4 + 2O2 CO2 + 2H2O C3H8 + 5O2 3CO2 + 4H2O

26. Combustion
Combustion reactions occur when 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”: 1) A Fuel (hydrocarbon) 2) Oxygen to burn it with 3) Something to ignite the reaction (spark)

27. Combustion
Products in combustion are ALWAYS carbon dioxide and water. (although incomplete burning does cause some by-products like carbon monoxide)

28. Combustion Practice
Complete and Balance the combustion equation ___C5H12 + ___O2

29. Combustion Practice
Balance the combustion equation __C5H12 + _8_O2 5CO2 + _6H2O

30. Unit 8 Chemical Reactions
Types of Reactions