Chemical Quantities
Practice Test
1.
How many moles of calcium are in 0.544 g of calcium?
a.
0.0136
b.
0.554
c.
3.11
d.
0.0773
2.
How many moles of chlorine are in 100 g chlorine (Cl)?
a.
2.82
b.
0.355
c.
64.6
d.
100
3.
What is the molar mass of arsenic?
a.
33 kg/mol
b.
74.9 g/mol
c.
74.9 u/mol
d.
33 lb/mol
4.
How many moles of sucrose, C
12
H
22
O
11
, are in 1222 g of sucrose?
a.
0.258
b.
3.57
c.
1.22
d.
10.8
5.
What is the empirical formula of a compound that is 66.0% calcium and 34.0% phosphorus?
a.
Ca
4
P
b.
CaP
3
c.
Ca
3
P
5
d.
Ca
3
P
2
6.
According to the equation 2HBr + Na
2
CO
3
NaBr + H
2
O + CO
2
, what volume of CO
2
at 1.230 atm and 325 K is produced by 50.0 g of HBr reacting with an excess of Na
2
CO
3
?
a.
22.4 L
b.
6.70 L
c.
50.0 L
d.
1.52 L
7.
What is the mass of 2.40 mol of copper?
a.
152 g
b.
3.78 mg
c.
26.5 kg
d.
5.65 g
8.
Calculate the mass in grams of 0.0790 moles of aluminum.
a.
1.0 g
b.
34 g
c.
2.1 g
d.
21 g
9.
How many atoms of carbon are in a pure sample of carbon having a mass of 72.0 g?
a.
3.6 x 10 23
b.
4.33 x 10 25
c.
3.6 x 10 24
d.
36 x 10 24
10.
The number of things in one mole is the ________________.
a.
atomic mass unit
b.
kilogram
c.
gram
d.
Avogadro constant
11.
What is the molar mass of potassium dichromate?
a.
176 g/mol
b.
294 g/mol
c.
88.3 g/mol
d.
102 g/mol
12.
The empirical formula for a compound is CH and its molar mass is 78 g/mol. What is the compound's molecular formula?
a.
C
10
H
10
b.
C
3
H
3
c.
CH
d.
C
6
H
6
13.
Calculate the number of moles of hydrogen atoms in 4.75 mol sulfuric acid.
a.
4.75 mol
b.
2.38 mol
c.
33.2 mol
d.
9.50 mol
14.
What is the molar mass of carbon dioxide?
a.
6.02 × 10
23
g/mol
b.
44.0 g/mol
c.
12.0 g/mol
d.
32.0 g/mol
15.
At STP, one molar volume is __________.
a.
6.02 × 10
23
L
b.
22.4 L
c.
10.0 L
d.
32.0 L
16.
Determine the number of atoms in 3.54 mol S.
a.
1.70 x 10 24
b.
2.13 x 10 24
c.
1.70 x 10 23
d.
2.13 x 10 23
17.
What is the theoretical yield of nitrogen gas if 200 g of sodium azide decomposes?
a.
400 g
b.
135 g
c.
200 g
d.
127 g
18.
How many moles of magnesium atoms is 7.32 × 10
26
atoms?
a.
1.22 × 10
3
mol
b.
6.02 × 10
3
mol
c.
8.23 × 10
26
mol
d.
4.44 × 10
1
mol
19.
What volume of HCl at STP can be produced by the reaction of 12.0 L of hydrogen and 24.0 L of chlorine, both at STP?
a.
36.0 L
b.
12.0 L
c.
24.0 L
d.
100.0 L
20.
A direct measurement on a sample of pure substance can be converted to a count of the number of particles through ________________.
a.
telemetry
b.
geometry
c.
theory
d.
stoichiometry
21.
What is the percent boron by mass in boric acid, H
3
BO
3
?
a.
17.50%
b.
38.00%
c.
22.10%
d.
45.30%
22.
2.52 g of diatomic oxygen occupies 3.00 L at 266 K. What is the pressure of the oxygen?
a.
123 kPa
b.
42.0 kPa
c.
33.5 Pa
d.
58.0 kPa
23.
If the theoretical yield of a reaction is 0.2100 g and the actual yield is 0.1880 g, what is the percent yield?
a.
89.50%
b.
11.00%
c.
51.30%
d.
112%
24.
80.0 g of butane burns according to the chemical equation 2C
4
H
10
+ 13O
2
8CO
2
+ 10H
2
O. What mass of oxygen reacts?
a.
286 g
b.
32 g
c.
1.28 kg
d.
416 g
25.
How many atoms are in 34.6 g of carbon?
a.
0.00554
b.
1.73 × 10
24
c.
2.88
d.
12.1 × 10
23
26.
How many hydrogen atoms are in one mole of hydrogen molecules?
a.
12.04 × 10
23
b.
2.02
c.
6.02 × 10
23
d.
1.01
27.
What is the volume of 3.66 mol of an ideal gas at 145 kPa and -23
o
C?
a.
22.8 L
b.
52.4 L
c.
100.6 L
d.
4.21 L
28.
What is the mass of 0.100 mol of sodium chloride?
a.
0.585 g
b.
0.355 g
c.
10.0 g
d.
0 g
