Chemistry, 11e (Brown/LeMay/Brusten/Murphy)
Chapter 3: Stoichiometry: Calculations with Chemical Formulas and Equations
1) What is the coefficient of O2 when the following equation is completed and balanced?
C4 H8O2  O2  __________
A) 2
B) 3
C) 5
D) 6
E) 1
Answer: C
2) Predict the product in the combination reaction below.
Al (s)  N2 (g)  __________
A) AlN
B) Al3 N
C) AlN2
D) Al3 N 2
E) AlN3
Answer: A
3) There are __________ sulfur atoms in 25 molecules of C4 H 4S2 .
A) 1.5 1025
B) 4.8 1025
C) 3.0 1025
D) 50
E) 6.02 1023
Answer: D
4) There are __________ hydrogen atoms in 25 molecules of C4 H 4S2 .
A) 25
B) 3.8 1024
C) 6.0 1025
D) 100
E) 1.5 1025
Answer: D
5) A sample of C3H8O that contains 200 molecules contains __________ carbon atoms.
A) 600
B) 200
C) 3.611026
D) 1.20 1026
E) 4.011025
Answer: A
Chemistry, 11e (Brown/LeMay/Brusten/Murphy)
Chapter 3: Stoichiometry: Calculations with Chemical Formulas and Equations
6) How many grams of hydrogen are in 46 g of CH4O ?
A) 5.8
B) 1.5
C) 2.8
D) 0.36
E) 184
Answer: A
7) How many grams of oxygen are in 65 g of C2 H 2O2 ?
A) 18
B) 29
C) 9.0
D) 36
E) 130
Answer: D
8) A 22.5-g sample of ammonium carbonate contains __________ mol of ammonium ions.
A) 0.468
B) 0.288
C) 0.234
D) 2.14
E) 3.47
Answer: A
9) What is the empirical formula of a compound that contains 27.0% S, 13.4% O, and 59.6% Cl by mass?
A) SOCl
B) SOCl2
C) S2OCl
D) SO2Cl
E) ClSO4
Answer: B
10) A compound is composed of only C, H, and O. The combustion of a 0.519-g sample of the compound
yields 1.24 g of CO2 and 0.255 g of H 2 O . What is the empirical formula of the compound?
A) C6 H 6O
B) C3H3O
C) CH3O
D) C2 H 6O5
E) C2 H6O2
Answer: B
Chemistry, 11e (Brown/LeMay/Brusten/Murphy)
Chapter 3: Stoichiometry: Calculations with Chemical Formulas and Equations
11) Combustion of a 1.031-g sample of a compound containing only carbon, hydrogen, and oxygen produced
2.265 g of CO2 and 1.236 g of H 2 O . What is the empirical formula of the compound?
A) C3H8O
B) C3H5O
C) C6 H16O2
D) C3H9O3
E) C3H 6 O3
Answer: A
12) Combustion of a 0.9835-g sample of a compound containing only carbon, hydrogen, and oxygen
produced 1.900 g of CO2 and 1.070 g of H 2 O . What is the empirical formula of the compound?
A) C2 H5O
B) C4 H10O2
C) C4 H11O2
D) C4 H10O
E) C2 H5O2
Answer: C
13) Magnesium and nitrogen react in a combination reaction to produce magnesium nitride:
In a particular experiment, a 9.27-g sample of N 2 reacts completely. The mass of Mg consumed is
__________ g.
A) 8.04
B) 24.1
C) 16.1
D) 0.92
E) 13.9
Answer: B
14) The combustion of ammonia in the presence of excess oxygen yields NO 2 and H 2 O :
The combustion of 28.8 g of ammonia consumes __________ g of oxygen.
A) 94.7
B) 54.1
C) 108
D) 15.3
E) 28.8
Answer: A
Chemistry, 11e (Brown/LeMay/Brusten/Murphy)
Chapter 3: Stoichiometry: Calculations with Chemical Formulas and Equations
15) Lead (II) carbonate decomposes to give lead (II) oxide and carbon dioxide:
How many grams of lead (II) oxide will be produced by the decomposition of 2.50 g of lead (II) carbonate?
A) 0.41
B) 2.50
C) 0.00936
D) 2.09
E) 2.61
Answer: D
16) What mass in grams of hydrogen is produced by the reaction of 4.73 g of magnesium with 1.83 g of
water?
A) 0.102
B) 0.0162
C) 0.0485
D) 0.219
E) 0.204
Answer: A
17) Silver(I) nitrate and aluminum chloride react with each other by exchanging anions:
What mass in grams of AgCl is produced when 4.22 g of AgNO3 react with 7.73 g of AlCl3 ?
A) 17.6
B) 4.22
C) 24.9
D) 3.56
E) 11.9
Answer: D
18) How many moles of magnesium oxide are produced by the reaction of 3.82 g of magnesium nitride with
7.73 g of water?
A) 0.114
B) 0.0378
C) 0.429
D) 0.0756
E) 4.57
Answer: A
19) A 3.82-g sample of magnesium nitride is reacted with 7.73 g of water.
The yield of MgO is 3.60 g. What is the percent yield in the reaction?
A) 94.5
B) 78.7
C) 46.6
D) 49.4
E) 99.9
Answer: B
Chemistry, 11e (Brown/LeMay/Brusten/Murphy)
Chapter 3: Stoichiometry: Calculations with Chemical Formulas and Equations
20) Solid aluminum and gaseous oxygen react in a combination reaction to produce aluminum oxide:
The maximum amount of Al2 O3 that can be produced from 2.5 g of Al and 2.5 g of O2 is __________ g.
A) 9.4
B) 7.4
C) 4.7
D) 5.3
E) 5.0
Answer: C
21) Sulfur and fluorine react in a combination reaction to produce sulfur hexafluoride:
The maximum amount of SF6 that can be produced from the reaction of 3.5 g of sulfur with 4.5 g of fluorine
is __________ g.
A) 12
B) 3.2
C) 5.8
D) 16
E) 8.0
Answer: C
22) Solid aluminum and gaseous oxygen react in a combination reaction to produce aluminum oxide:
In a particular experiment, the reaction of 2.5 g of Al with 2.5 g of O2 produced 3.5 g of Al2 O3 . The % yield
of the reaction is __________.
A) 74
B) 37
C) 47
D) 66
E) 26
Answer: A
23) Which one of the following substances is the product of this combination reaction?
Al (s) I2 (s)  
A) AlI 2
B) AlI
C) AlI3
D) Al2 I3
E) Al3I2
Answer: C
Chemistry, 11e (Brown/LeMay/Brusten/Murphy)
Chapter 3: Stoichiometry: Calculations with Chemical Formulas and Equations
24) Gaseous argon has a density of 1.40 g/L at standard conditions. How many argon atoms are in 1.00 L of
argon gas at standard conditions?
A) 4.76 1022
B) 3.43 10 25
C) 2.1110 22
D) 1.59 10 25
E) 6.02 1023
Answer: C
25) A nitrogen oxide is 63.65% by mass nitrogen. The molecular formula could be __________.
A) NO
B) NO 2
C) N 2 O
D) N 2 O4
E) either NO 2 or N 2 O4
Answer: C
26) Sulfur and oxygen react to produce sulfur trioxide. In a particular experiment, 7.9 grams of SO3 are
produced by the reaction of 5.0 grams of O2 with 6.0 grams of S. What is the % yield of SO3 in this
experiment?
A) 32
B) 63
C) 75
D) 95
E) 99
Answer: D