The document contains examples of various types of chemical reactions: a) Combustion reactions of hydrocarbons and alcohols reacting with oxygen. b) Decomposition reactions of ammonium nitrate decomposing. c) Combination reactions of nitrogen and hydrogen forming ammonia, and potassium oxide reacting with water. d) Stoichiometric calculations involving moles, masses, and molecules in several chemical equations.

1. 3.20 Balance the following:
a) COMBUSTION
C3H6 + O2  CO2 + H2O
2C3H6 + 9O2  6CO2 + 6H2O
b) DECOMPOSITION
NH4NO3  N2O + H2O
NH4NO3  N2O + 2H2O
c) COMBUSTION
C5H6O + O2  CO2 + H2O
C5H6O + 6O2  5CO2 + 3H2O
d) COMBINATION
N2 + H2  NH3
N2 + 3H2  2NH3
e) COMBINATION
K2O + H2O  KOH
K2O + H2O  2KOH

2. 3.34
a) Mass of 5.50x10-3 moles of CdS
Cd  112
144 gCdS
S  32 5.76 x10 −3 molCdS * = 0.829 gCdS
molCdS
144
b) Moles of NH4Cl in 112.6g
N  14
H1x4=4
Cl  35.5
53.5
1molNH 4Cl
112.6 gNH 4Cl * = 2.10 gNH 4Cl
53.5 gnH 4Cl
c) Molecules in 1.305 x 10-2 moles of C6H6
−2 6.02 *10 23 molecules
1.305 *10 molC6 H 6 * = 7.86 *10 23 molecules
mol
d) Oxygen atoms in 4.88 x 10-3 mol Al(NO3)
−3 6.02 *10 23 molecules 9 O atoms
4.88 *10 molAl ( NO3 ) 3 * * = 2.64 *10 23 O atoms
mol molecule

3. 3.58 C6H12O6  2C2H5OH + 2CO2
2 mol CO 2
a) 0.400 mol EtOH * = 0.800 mol CO 2
1 mol EtOH
b)
Molecule C6H12O6 C2H5OH CO2
C 12 6 72 C 12 6 24 C 12 1 12
O 16 6 96 O 16 1 16 O 16 2 32
H 1 12 12 H 1 6 6
Total 18 45 44
0
1 mol EtOH 1 mol glucose 180 g glucose
7.5 g EtOH * * * = 15 g glucose
45 g EtOH 2 mol EtOH 1 mol glucose
c)
1 mol EtOH 2 mol CO 2 44 g CO 2
7.5 g EtOH * * * = 7.3 g glucose
45 g EtOH 2 mol EtOH 1 mol CO 2

4. 3.60
a) Balance: Fe2O3 + CO  Fe + CO2
Fe2O3 + 3CO  2Fe + 3CO2
b)
1000g 1 mol Fe 2 O 3 3 mol CO 28 g CO
0.150 Kg Fe 2 O 3 * * * * = 78.95 g CO
1 Kg 159.6 g Fe 2 O 3 1 mol Fe 2 O 3 mol CO
c)
grams Fe:
1000g 1 mol Fe 2 O 3 2 mol Fe 55.8 g Fe
0.150 Kg Fe 2 O 3 * * * * = 104.9 g Fe
1 Kg 159.6 g Fe 2 O 3 1 mol Fe 2 O 3 mol Fe
grams CO2
1000g 1 mol Fe 2 O 3 3 mol CO 2 44 g CO 2
0.150 Kg Fe 2 O 3 * * * * = 124.0 g CO 2
1 Kg 159.6 g Fe 2 O 3 1 mol Fe 2 O 3 mol CO 2
d)
Fe2O3 + 3CO  2Fe + 3CO2
150g + 78.9g = 104.9g +124g
228.9g = 228.9 g