Chapter 11:
The Mole
Practice Test
1.
What mass of calcium metal could be obtained from 1 kg of limestone that is 50.0% pure CaCO
3
?
a.
0.05 kg
b.
0.2 kg
c.
0.5 kg
d.
0.4 kg
Hint
2.
What relationship is described by the formula below?
(mass of the element/mass of the compound) × 100
a.
empirical formula
b.
mole ratio
c.
percent composition
d.
Avogadro’s number
Hint
3.
How many particles are present in one mole of particles?
a.
3.0 × 10
8
b.
1
c.
12
d.
6.02 × 10
23
Hint
4.
How many moles of C
3
H
8
are present in 451 g C
3
H
8
?
a.
3.84 mol
b.
1.44 mol
c.
0.879 mol
d.
10.2 mol
Hint
5.
How can the actual molecular formula be determined?
a.
from the molar mass multiplied by the mass of the empirical formula
b.
from the molar mass alone
c.
from the empirical formula alone
d.
from the molar mass divided by the mass of the empirical formula
Hint
6.
What is the percent composition of carbon dioxide CO
(2)
?
a.
33% C and 66% O
b.
27% C and 73% O
c.
50% C and 50% O
d.
73% C and 27% O
Hint
7.
How is one gram defined?
a.
10 moles of amu
b.
one mole of amu
c.
one mole of protons
d.
0.1 mole of amu
Hint
8.
What is the mass of 1.0 × 10
12
molecules of O
2
?
a.
1.9 × 10
13
g
b.
5.3 × 10
-11
g
c.
6.0 × 10
11
g
d.
2.7 × 10
-11
g
Hint
9.
A sample of a compound is found to contain 0.404 grams of Fe and 0.174 grams of O. What is the empirical formula for this compound?
a.
FeO
b.
Fe
3
O
4
c.
Fe
2
O
3
d.
FeO
2
Hint
10.
Which word indicates that two water molecules are associated with a substance in a chemical compound?
a.
tri-
b.
di-
c.
mono-
Hint
11.
An empirical formula mass is found to be 17 g/mol. The molar mass is found to be 34 g/mol. What is the number of empirical formula units in this molar mass?
a.
2 units
b.
0.5 unit
c.
1 unit
d.
17 units
Hint
12.
How many moles of atoms are present in one mole of water?
a.
2 mol
b.
1 mol
c.
3 mol
d.
6 mol
Hint
13.
What is the molar mass of H
2
CrO
4
?
a.
52 g
b.
118 g
c.
64 g
d.
2 g
Hint
14.
A compound contains sulfur, oxygen, and chlorine. Analysis of a sample showed that it contained by mass 26.95% sulfur and 59.61% chlorine. What is the simplest formula for this compound?
a.
SO
2
Cl
2
.
b.
SOCl
c.
SOCl
2
.
d.
SO
2
Cl
Hint
15.
What is the mass of 5.0 × 10
21
molecules of water?
a.
0.15 g
b.
6.02 x 10
23
g
c.
5.0 g
d.
8.3 x 10
-3
g
Hint
16.
A compound that has a specific number of water molecules bound to the structure is ______________?
a.
aqueous
b.
waterlogged
c.
an anhydrate
d.
a hydrate
Hint
17.
What mass of iron is contained in 62.8 grams of pyrite FeS
(2)
?
a.
29.2 g
b.
40.3 g
c.
31.7 g
d.
58.5 g
Hint
18.
How many molecules of ammonia are present in 34.0 g of ammonia NH
(3)
?
a.
6.02 × 10
23
b.
1.77 × 10
22
c.
1.20 × 10
24
d.
34
Hint
19.
What is the mass of one mole of carbon-12 atoms?
a.
12 amu
b.
6 amu
c.
6 grams
d.
12 grams
Hint
20.
A 4.628-g sample of an iron oxide was found to contain 3.348 g of iron and 1.280 g of oxygen. What is the simplest formula for this compound?
a.
FeO
2
b.
Fe
2
O
3
c.
Fe
3
O
4
d.
FeO
Hint
