Chapter 11:
The Mole
Practice Test
1.
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.
FeO
2
c.
Fe
3
O
4
d.
Fe
2
O
3
Hint
2.
Which word indicates that two water molecules are associated with a substance in a chemical compound?
a.
di-
b.
mono-
c.
tri-
Hint
3.
What is the mass of 1.0 × 10
12
molecules of O
2
?
a.
1.9 × 10
13
g
b.
6.0 × 10
11
g
c.
2.7 × 10
-11
g
d.
5.3 × 10
-11
g
Hint
4.
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.
SOCl
b.
SO
2
Cl
c.
SO
2
Cl
2
.
d.
SOCl
2
.
Hint
5.
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.
Fe
3
O
4
b.
FeO
2
c.
FeO
d.
Fe
2
O
3
Hint
6.
What is the mass of 5.0 × 10
21
molecules of water?
a.
6.02 x 10
23
g
b.
0.15 g
c.
5.0 g
d.
8.3 x 10
-3
g
Hint
7.
What is the molar mass of H
2
CrO
4
?
a.
118 g
b.
64 g
c.
52 g
d.
2 g
Hint
8.
How many moles of hydrogen atoms are present in 2.0 moles of ammonia NH
(3)
?
a.
2.0 mol
b.
8.0 mol
c.
3.0 mol
d.
6.0 mol
Hint
9.
Calculate the number of atoms in 4.00 × 10
-5
g sodium.
a.
5.54 × 10
20
atoms
b.
3.24 × 10
23
atoms
c.
1.05 × 10
18
atoms
d.
3.92 × 10
19
atoms
Hint
10.
How many moles of hydrogen are present in 2.0 grams of hydrogen gas?
a.
1.0 mol
b.
2.0 mol
c.
4.0 mol
d.
0.5 mol
Hint
11.
Analysis of a covalent compound showed that it contained 14.4% hydrogen and 85.6% carbon by mass. What is the empirical formula for this compound?
a.
CH
2
b.
CH
2
c.
CH
d.
C
2
H
3
Hint
12.
How many moles of C
3
H
8
are present in 451 g C
3
H
8
?
a.
10.2 mol
b.
1.44 mol
c.
3.84 mol
d.
0.879 mol
Hint
13.
How many moles of atoms are present in one mole of water?
a.
1 mol
b.
6 mol
c.
2 mol
d.
3 mol
Hint
14.
What is the mass of one mole of carbon-12 atoms?
a.
6 amu
b.
12 amu
c.
6 grams
d.
12 grams
Hint
15.
A compound that has a specific number of water molecules bound to the structure is ______________?
a.
aqueous
b.
waterlogged
c.
a hydrate
d.
an anhydrate
Hint
16.
How can the actual molecular formula be determined?
a.
from the empirical formula alone
b.
from the molar mass multiplied by the mass of the empirical formula
c.
from the molar mass alone
d.
from the molar mass divided by the mass of the empirical formula
Hint
17.
What relationship is described by the formula below?
(mass of the element/mass of the compound) × 100
a.
mole ratio
b.
percent composition
c.
Avogadro’s number
d.
empirical formula
Hint
18.
What is the SI base unit used to measure the amount of a substance?
a.
mole
b.
kilogram
c.
kelvin
d.
meter
Hint
19.
How many molecules of ammonia are present in 34.0 g of ammonia NH
(3)
?
a.
1.77 × 10
22
b.
1.20 × 10
24
c.
34
d.
6.02 × 10
23
Hint
20.
What mass of calcium metal could be obtained from 1 kg of limestone that is 50.0% pure CaCO
3
?
a.
0.2 kg
b.
0.5 kg
c.
0.05 kg
d.
0.4 kg
Hint
