Chapter 12:
Chemical Quantities
Practice Test
1.
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.
50.0 L
c.
1.52 L
d.
6.70 L
Hint
2.
What is the molar mass of carbon dioxide?
a.
44.0 g/mol
b.
32.0 g/mol
c.
6.02 × 10
23
g/mol
d.
12.0 g/mol
Hint
3.
The number of things in one mole is the ________________.
a.
atomic mass unit
b.
Avogadro constant
c.
gram
d.
kilogram
Hint
4.
What is the mass of 0.100 mol of sodium chloride?
a.
10.0 g
b.
0.585 g
c.
0.355 g
d.
0 g
Hint
5.
2.52 g of diatomic oxygen occupies 3.00 L at 266 K. What is the pressure of the oxygen?
a.
33.5 Pa
b.
123 kPa
c.
42.0 kPa
d.
58.0 kPa
Hint
6.
How many moles of sucrose, C
12
H
22
O
11
, are in 1222 g of sucrose?
a.
10.8
b.
1.22
c.
0.258
d.
3.57
Hint
7.
How many atoms are in 34.6 g of carbon?
a.
0.00554
b.
12.1 × 10
23
c.
1.73 × 10
24
d.
2.88
Hint
8.
A direct measurement on a sample of pure substance can be converted to a count of the number of particles through ________________.
a.
geometry
b.
stoichiometry
c.
telemetry
d.
theory
Hint
9.
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.
24.0 L
b.
100.0 L
c.
36.0 L
d.
12.0 L
Hint
10.
How many moles of calcium are in 0.544 g of calcium?
a.
0.554
b.
0.0773
c.
0.0136
d.
3.11
Hint
11.
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
3
H
3
b.
CH
c.
C
10
H
10
d.
C
6
H
6
Hint
12.
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.
11.00%
b.
51.30%
c.
112%
d.
89.50%
Hint
13.
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.
32 g
b.
1.28 kg
c.
286 g
d.
416 g
Hint
14.
At STP, one molar volume is __________.
a.
6.02 × 10
23
L
b.
22.4 L
c.
10.0 L
d.
32.0 L
Hint
15.
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
Hint
16.
According to Avogadro's principle, how many liters of hydrogen gas react with 30.0 L of oxygen gas at the same temperature and pressure to form water?
a. 30.0 L
b. 60.0 L
c. 10.0 L
d. 45.0 L
Hint
17.
What is the molar mass of potassium dichromate?
a.
88.3 g/mol
b.
176 g/mol
c.
294 g/mol
d.
102 g/mol
Hint
18.
What mass of CO
2
is produced in the reaction described in question 13?
a.
44.0 g
b.
0.477 g
c.
242 g
d.
3.85 kg
Hint
19.
How many moles of magnesium atoms is 7.32 × 10
26
atoms?
a.
1.22 × 10
3
mol
b.
4.44 × 10
1
mol
c.
6.02 × 10
3
mol
d.
8.23 × 10
26
mol
Hint
20.
What is the percent boron by mass in boric acid, H
3
BO
3
?
a.
22.10%
b.
38.00%
c.
17.50%
d.
45.30%
Hint
