Balancing Chemical Equations
CA Standards
Students know how to describe
chemical reactions by writing
balanced equations.
Law of Conservation of Mass
• In ordinary chemical reactions, the
total mass of reacting substances is
equal to the total mass of products
– All atoms on the reactant side must
appear on the product side, and in equal
numbers
– No new elements may appear
– No elements may disappear
Synthesis Reactions
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
___CaO + ___H2O  ___Ca(OH)2
___P4 + ___O2  ___P2O5
___Ca + ___O2  ___CaO
___Cu + ___S8  ___ CuS
___CaO + ___H2O  ___Ca(OH)2
___S8 + ___O2  ___SO2
___H2 + ___N2  ___NH3
___H2 + ___Cl2  ___HCl
___Ag +
___S8  ___Ag2S
___Cr + ___O2  ___Cr2O3
___Al + ___Br2  ___AlBr3
___Na + ___I2  ___NaI
___H2 + ___O2  ___H2O
___Al + ___O2  ___Al2O3
Decomposition Reactions
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
___BaCO3  ___BaO
+ ___CO2
___MgCO3  ___MgO + ___CO2
___K2CO3  ___K2O + ___CO2
___Zn(OH)2  ___ZnO + ___H2O
___Fe(OH)2  ___FeO + ___H2O
___Ni(ClO3)2  ___NiCl2 + ___O2
___NaClO3  ___NaCl + ___O2
___KClO3  ___KCl + ___O2
___H2SO4  ___H2O + ___SO3
___H2CO3  ___H2O + ___CO2
___Al2O3  ___Al + ___O2
___Ag2O  ___Ag + ___O2
Decomposition Reactions
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
___BaCO3  ___BaO
+ ___CO2
___MgCO3  ___MgO + ___CO2
___K2CO3  ___K2O + ___CO2
___Zn(OH)2  ___ZnO + ___H2O
___Fe(OH)2  ___FeO + ___H2O
___Ni(ClO3)2  ___NiCl2 + ___O2
___NaClO3  ___NaCl + ___O2
___KClO3  ___KCl + ___O2
___H2SO4  ___H2O + ___SO3
___H2CO3  ___H2O + ___CO2
___Al2O3  ___Al + ___O2
___Ag2O  ___Ag + ___O2
Single Replacement Reactions
27.
___AgNO3
28.
___AlBr3
29.
___NaI
30.
___Ca
31.
___Mg
32.
___ Zn
33.
___K
34.
___Na
 ___Ni(NO3)2
+ ___Ni
+
+
+

___Cl2
___Br2

___NaBr
___HCl

___CaCl2
+ ___HNO3 

+ ___H2SO4
+ ___H2O
+
___AlCl3
___H2O

+
+
+
___ZnSO4
+
___NaOH
___Ag
___Br2
___I2
___Mg(NO3)2 +
___KOH

+
+
___H2
___H2
___H2
___H2
+
___H2
Double Replacement Reactions
35.
___AlI3
+
___HgCl2

____AlCl3
36.
___HCl
+
___NaOH

___NaCl
37.
___BaCl2
___H2SO4

___BaSO4
38.
___Al2(SO4)3
39.
___AgNO3
40.
___CuBr2
41.
___Ca(C2H3O2)2 + ___Na2CO3
42.
___NH4Cl + ___Hg2(C2H3O2)2  ___NH4 C2H3O2 +
43.
___Ca(NO3)2
44.
___FeS
45.
___Cu(OH)2 + ___HC2H3O2
46.
___Ca(OH)2
47.
___CaBr2
+
+
+
___AlCl3
+
+
___HCl
___HCl
+
+

___K3PO4
+

___Ca(OH)2
___KOH
+
___HCl
___Al(OH)3
___CaCl2


+
+
+
+
___KNO3
+ ___NaC2H3O2
___Hg2Cl2
+ ___HNO3
___H2S
___Cu(C2H3O2)2
___Ca3(PO4)2
___Ca(OH)2
___CaSO4
___AlBr3
 ___CaCO3
___FeCl2

___H2O
___CuCl2

___H3PO4
____HgI2(ppt)
___Ag3PO4


+
+
+
+
___H2O
___H2O
___KBr
Combustion Reactions
+
___O2

48.
___CH4
___CO2
+
___H2O
49.
___C2H6
+
___O2

___CO2
+
___H2O
50.
___C3H8
+
___O2

___CO2
+
___H2O
51.
___C4H10
+
___O2

___CO2
+
___H2O
52.
___C5H12
+
___O2

___CO2
+
___H2O
53.
___C6H14
+
___O2

___CO2
+
___H2O
54.
___C2H4
+
___O2

___CO2
+
___H2O
55.
___C2H2
+
___O2

___CO2
+
___H2O
56.
___C6H6
+
___O2

___CO2
+
___H2O