1. Types of Chemical Reactions

2. CH4(g) + 2O2(g)  CO2(g) + 2H2O(g)
A. Combustion
the burning of any substance in O2 to produce heat
A + O2  B
CH4(g) + 2O2(g)  CO2(g) + 2H2O(g)

3. A. Combustion C3H8(g)+ O2(g)  5 3 4 CO2(g)+ H2O(g) Products:
contain oxygen
hydrocarbons form CO2 + H2O
C3H8(g)+ O2(g) 
CO2(g)+ H2O(g)

4. B. Synthesis
the combination of 2 or more substances to form a compound
only one product
A + B  AB

5. B. Synthesis
H2(g) + Cl2(g)  2 HCl(g)

6. Al(s)+ Cl2(g)  2 3 2 AlCl3(s) B. Synthesis Products:
ionic - cancel charges
covalent - hard to tell
Al(s)+ Cl2(g) 
AlCl3(s)

7. Practice
Predict the products. Write and balance the following synthesis reaction equations.
Sodium metal reacts with chlorine gas
Solid Magnesium reacts with fluorine gas
Aluminum metal reacts with fluorine gas

8. C. Decomposition
AB  A + B

9. a compound breaks down into 2 or more simpler substances
only one reactant

10. C. Decomposition
2 H2O(l)  2 H2(g) + O2(g)

11. C. Decomposition 2 2 KBr(l)  K(s) + Br2(l) Products:
binary - break into elements
others - hard to tell
KBr(l) 
K(s) + Br2(l)

12. A + BC  B + AC D. Single Replacement
one element replaces another in a compound
metal replaces metal (+)
nonmetal replaces nonmetal (-)
A + BC  B + AC

13. Cu(s) + 2AgNO3(aq)  Cu(NO3)2(aq) + 2Ag(s)
D. Single Replacement
Cu(s) + 2AgNO3(aq)  Cu(NO3)2(aq) + 2Ag(s)

14. D. Single Replacement Fe(s)+ CuSO4(aq)  Cu(s)+ FeSO4(aq)
Products:
metal  metal (+)
nonmetal  nonmetal (-)
free element must be more active (check activity series)
Fe(s)+ CuSO4(aq) 
Cu(s)+ FeSO4(aq)
Br2(l)+ NaCl(aq) 
N.R.

15. AB + CD  AD + CB E. Double Replacement
ions in two compounds “change partners”
cation of one compound combines with anion of the other
AB + CD  AD + CB

16. Pb(NO3)2(aq) + K2CrO4(aq)  PbCrO4(s) + 2KNO3(aq)
E. Double Replacement
Pb(NO3)2(aq) + K2CrO4(aq)  PbCrO4(s) + 2KNO3(aq)

17. E. Double Replacement Pb(NO3)2(aq)+ KI(aq)  2 2 PbI2(s)+ KNO3(aq)
Products:
switch negative ions
one product must be insoluble (check solubility table)
Pb(NO3)2(aq)+ KI(aq) 
PbI2(s)+ KNO3(aq)
NaNO3(aq)+ KI(aq) 
N.R.

18. one
Two or more
Yes No
Are both reactants Ionic compounds?
Is the element O2? No
Yes
Yes
Are both reactancts single elements?
Double Displacement
Are the only elements present in the reactants side C, H, and O No No
Yes No
Yes
Combustion
Single Displacement
Synthesis

19. No, Ni is below Na Yes, Li is above Zn Yes, Al is above Cu
We have looked at several reactions:
Fe + CuSO4  Cu + Fe2(SO4)3
Li + H2O  LiOH + H2
Such experiments reveal trends. The activity series ranks the relative reactivity of metals.
It allows us to predict if certain chemicals will undergo single displacement reactions when mixed: metals near the top are most reactive and will displacing metals near the bottom.
Q: Which of these will react?
Fe + CuSO4 
Ni + NaCl 
Li + ZnCO3 
Al + CuCl2  K Na Li Ca Mg Al Zn Fe Ni Sn Pb H Cu Hg Ag Au
No, Ni is below Na
Yes, Li is above Zn
Yes, Al is above Cu
Yes, Fe is above Cu
Cu + Fe2(SO4)3
NR (no reaction)
Zn + Li2CO3
Cu + AlCl3

20. A: No for cold, yes if it is hot/steam Mg + H2O  H2 + Mg(OH)2 acid
H is the only nonmetal listed. H2 may be displaced from acids or can be given off when a metal reacts with H2O (producing H2 + metal hydroxide). The reaction with H2O depends on metal reactivity & water temp.
Q: will Mg react with H2O? K Na Li Ca Mg Al Zn Fe Ni Sn Pb H Cu Hg Ag Au
cold H2O
hot H2O
steam
A: No for cold, yes if it is hot/steam
Mg + H2O 
H2 + Mg(OH)2
acid
Q: Zn + HCl 
H2 + ZnCl2
Complete these reactions:
Al + H2O(steam) 
Cu + H2O 
Ca + H2SO4 
Na + H2O 
H2 + Al(OH)3 NR
H2 + CaSO4
H2 + NaOH

21. Other Activity Series Information
All metals will have a specific place in the activity series. For simplicity, only the most common metals are shown.
The metals near the top of the activity series are more reactive because their valence electrons are more easily removed.
On tests and exams the activity series may appear as K, Na, … Ag, Au; you must remember that K is reactive, Au is not.
If the valence of a metal is not indicated in the question, use its most common valence (in bold on your periodic table) to determine the correct chemical formula.

22. Fluorine
Chlorine
Bromine
Iodine

25. Even if everything is soluble, look for signs of a reaction
H2SO4(aq) + 2NaOH(aq)  Na2SO(aq) + 2H2O(l)
Heat is given off