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