The Mole
Practice Test
1.
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.
Fe
2
O
3
d.
FeO
2.
How many particles are present in one mole of particles?
a.
6.02 x 10
23
b.
12
c.
1
d.
3.0 x 10
8
3.
What mass of calcium metal could be obtained from 1 kg of limestone that is 50.0% pure CaCO
3
?
a.
0.4 kg
b.
0.2 kg
c.
0.5 kg
d.
0.05 kg
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.
10.2 mol
d.
0.879 mol
5.
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.
0.5 unit
b.
2 units
c.
1 unit
d.
17 units
6.
Which word indicates that two water molecules are associated with a substance in a chemical compound?
a.
an
-
b.
di
-
c.
tri
-
d.
mono
-
7.
How can the actual molecular formula be determined?
a.
from the molar mass alone
b.
from the molar mass divided by the mass of the empirical formula
c.
from the empirical formula alone
d.
from the molar mass multiplied by the mass of the empirical formula
8.
How many moles of atoms are present in one mole of water?
a.
6 mol
b.
2 mol
c.
1 mol
d.
3 mol
9.
What is the correct chemical formula for barium hydroxide octahydrate?
Prefix
Molecules H
2
O
Mono-
1
Di-
2
Tri-
3
Tetra-
4
Penta-
5
Hexa-
6
Hepta-
7
Octa-
8
Deca-
10
a.
Ba(OH)
2
. H
2
O
b.
8Ba(OH)
2
. H
2
O
c.
Ba(OH)
2
. 8H
2
O
d.
Ba . 8(OH)
2
10.
How many moles of hydrogen are present in 2.0 grams of hydrogen gas?
a.
0.5 mol
b.
1.0 mol
c.
4.0 mol
d.
2.0 mol
11.
Determine the number of atoms in 3.54 mol S.
a.
2.13 x 10
23
b.
1.70 x 10
23
c.
2.13 x 10
24
d.
1.70 x 10
24
12.
What relationship is described by the formula below? (mass of the element/mass of the compound) x 100
a.
mole ratio
b.
percent composition
c.
empirical formula
d.
Avogadro’s number
13.
A compound that has a specific number of water molecules bound to the structure is ______________?
a.
waterlogged
b.
an anhydrate
c.
a hydrate
d.
aqueous
14.
What is the mass of 5.0 x 10
21
molecules of water?
a.
5.0 g
b.
6.02 x 10
23
g
c.
0.15 g
d.
8.3 x 10
-3
g
15.
What is the SI base unit used to measure the amount of a substance?
a.
kelvin
b.
mole
c.
meter
d.
kilogram
16.
How many moles of chlorine are in 100 g chlorine (Cl)?
Element
Molar Mass (g/mol)
Hydrogen
1.01
Carbon
12.01
Chlorine
35.45
a.
100
b.
0.355
c.
2.82
d.
64.6
17.
Calculate the number of moles of hydrogen atoms in 4.75 mol sulfuric acid.
a.
4.75 mol
b.
33.2 mol
c.
9.50 mol
d.
2.38 mol
